thesis definition in math

Writing Your Thesis

The thesis should be the heart of your graduate school career. It will certainly be the most involved and difficult thing you do while in grad school.

Of course, before writing the thesis, one needs to have research to report. To make things easier on yourself, it’s a good idea to record your results as you work. Don’t rely on your memory to save you when you need to write everything down in your thesis! While you needn’t have everything written in final draft, having a detailed account of your research progress is a great idea. When you start your research, you and your advisor should try to establish a goal for your thesis as soon as possible. Performing research without a goal can be very difficult and even more frustrating.

When one does mathematical research, one rarely knows exactly where they are going. Gaining mathematical intuition comes from lots of hard work, not simply being very smart. A tried and true method for doing research is to do lots of examples, and make simplifying assumptions when needed. Before you can prove a theorem, you need a conjecture; these aren’t going to just fall in your lap! The idea is that after seeing enough examples, one can make a general conjecture and then hopefully prove it.

It’s a good idea to find out who else in the community (both in and out of the department) thinks about your field. You may find it useful to contact these people from time to time. This serves multiple purposes: you’ll lessen the chance of duplicating someone else’s research; you’ll find multiple sources of advice. While your advisor will likely be the single biggest source of help in writing your thesis, they needn’t be your only source. Talking to many people about your work will give you several different perspectives on the same thing. Seeing the same thing in different ways can be invaluable in understanding something.

When you have enough results such that you and your advisor are satisfied, you need to organize your work into one coherent document. This can be a highly non-trivial task! Make sure that your problem is stated clearly, along with why it is important, and how you solved it. Your thesis shouldn’t simply be a list of definitions, theorems, and proofs; there should be quite a bit of prose to explain the mathematical ambiance of your work. What is the motivation for even thinking about this problem? The more people that find your research interesting, the better.

Please refer to this manual for guidelines on formatting your thesis:  http://grad.ucsd.edu/_files/academics/BlueBook%202017-18%20updated%204.13.18.pdf

Defending Your Thesis

Setting a time to defend your dissertation can be frustrating. Contact your committee members well in advance in order to check availability and schedule a date/time.

You would think that finding a time for 6 people to meet would be an easy task. However, it can be exceedingly difficult. You may need to be very flexible and accommodating in order to make things work. You may also need to be persistent about asking if you have a non-responsive committee member.

Please carefully review these guidelines regarding committee attendance:

Department  Policy on Graduate Examination  Format:

Effective Fall 2022, the default format of a graduate examination in the Mathematics Department is  in person , i.e.,  all the committee members and the student are physically present in the same room for a scheduled examination . (This is set by the Division of GEPA.) However, when an unexpected situation arises and affects a committee member’s ability to participate in the examination synchronously, and when the student agrees, a remote or hybrid examination is allowed and can be decided by the committee chair or co-chairs. The following guidelines should be followed to arrange a remote or hybrid, synchronous examination:

• In forming the committee, the student needs to provide different examination options, in person, remote, or hybrid, to potential faculty committee members, and based on the conversation, the student can decide whether or not they want the faculty member on their committee. If such conversation did not take place, and if an unexpected situation arises, the faculty committee member can request remote examination, and can be released from the committee duty should the student refuse the request.
• In general, the graduate student is not allowed to opt for a remote examination unless there are extenuating circumstances, such as illness, travel difficulties related to visa problems, or a graduation deadline. Under such circumstances, the committee chair can decide to reschedule an in-person examination, or have a remote or hybrid examination.
• According to the Division of GEPA, there must be sufficient expertise among present members to examine the student. If a committee member must be absent for the scheduled exam, it is permissible for one absent committee member to examine the candidate on a separate date. The committee chair, or one co-chair, must participate synchronously in the scheduled exam.

Make sure to inform the PhD staff advisor in advance if any of your committee members will not be physically present.

During this scheduling phase, you also want to schedule your “Preliminary Appointment” with Graduate Division:  https://gradforms.ucsd.edu/calendar/index.php  – this appointment is optional but highly recommended! The purpose of this appointment is for them to check the margins and the formatting of your dissertation. While the above information should get you through this part without any problem, sometimes there are minor issues that arise and must be confronted (for example, published work that shows up in your dissertation has some extra requirements associated to it). The meeting should last about 30 minutes and you’ll receive a couple questionnaires to complete before your final appointment. You will also be required to schedule a Final Appointment with Graduate Division – allow at least a few days between your defense and your final appointment in order to finalize department paperwork.

In addition, the following information is critical to you completing your thesis, defending it, and completing your PhD:

• The university requires that your committee members each have a good readable draft of your dissertation at least FOUR WEEKS before your final defense.
• It  is your responsibility  to make arrangements with each committee member for the date and time of your defense.  Room reservations should be made at the Front Desk (in person or email to  [email protected])
• The  Final Report  form must have the original signatures of all members of the doctoral committee; the  Final Report  must also be signed by the program chair. (The  Final Report  form is initiated by the graduate coordinator and signatures are obtained from each faculty member through DocuSign.). Proxy signatures are not accepted.
• After your examination, committee chair emails PhD staff advisor confirming the passing of the defense. PhD staff advisor prepares Final Report through DocuSign.
• The final version of the thesis must conform to procedures outlined in the " Preparation and Submission Manual for Doctoral Dissertations and Master's Theses "
• The student submits the final approved dissertation to the Graduate Division  at the final document review  (the  Final Report  form is routed electronically from the program’s graduate coordinator via DocuSign). Final approval and acceptance of the dissertation by the Dean of the Graduate Division (on behalf of the University Archivist and Graduate Council) represents the final step in the completion of all requirements for the doctoral degree.

A few other suggestions:

About a week before you defend, you should send an email to your committee to remind them that your defense is coming, and you might even want to send a day-before or day-of reminder.

You should discuss the details of your defense with your advisor, but it’s basically a 50-minute talk where you highlight the main results of your dissertation. The audience is usually your committee plus a few graduate students.

Once Graduate Division has signed off on your thesis, it is time to submit your thesis online to Proquest/UMI. When you do this, they give you an option to purchase bound copies of your thesis from them. This is not particularly appealing for three reasons:

• They are rather pricey, about $40-$60 per copy
• They will print it exactly as you submitted it, according to Graduate Division standards: double-spaced, 8.5×11, etc, which doesn’t make for an attractive book. (How many of the math books on your shelf are 8.5×11 double-spaced?)

Fortunately, another option is available: self-publishing services. Originally these were intended for authors who had written a book, but couldn’t find a publisher for it, so they’d have it printed at their own expense. Nowadays, there are online sites filling this market, where you submit your manuscript and design the book yourself through their site. They can print on demand, so there is no minimum number of copies to order, and they can be quite inexpensive. A former graduate student, Nate Eldredge, chose to go with Lulu, so this article will describe that service.

You can begin by creating an account on Lulu’s site, which is pretty self-explanatory. They have several different book types available. I decided to go with a 6×9 “casewrap hardcover”, which is a pretty standard size and style for a book. If you have a yellow Springer book on your shelf, that’s a pretty good facsimile of what we’re talking about here.

The main issue, then, is reformatting the thesis into a 6×9 format. Fortunately, LaTeX makes this pretty easy. Pretty much, you just need to swich from the UCSD thesis class to the standard LaTeX book class and make a few other changes. Here is a modified version of the UCSD thesis template, modified to fit this format. Nate put comments in various places indicating the relevant changes and choices he made. In several places he took advantage of the fact that he no longer had to conform to OGS’s awkward requirements to make the thesis more “book-like” and remove some things that wouldn’t appear in a book. It shouldn’t take you more than an hour or two to convert your thesis file, depending how fastidious you are. (If you don’t want to go to this trouble, Lulu will also print 8.5×11 books. You could use your existing PDF without change. It may not look as pretty, but it will still be cheaper than UMI.)

Note that you should check carefully for overfull \hbox’es when you compile the thesis, because changing the paper size may have caused things to run outside the margins or off the page. You may have to manually break up long equations or reword paragraphs. Also, the book class will insert several apparently blank pages; these relate to the fact that the book will be printed double-sided, and guarantee that certain things always appear on the left- or right-hand side of a spread. If you want a book-like effect, you should not try to defeat this.

Once you’ve generated an appropriate 6×9 PDF file and uploaded it to Lulu, you can design a cover for it. They have a couple of different interfaces. For his thesis, Nate created a pretty simple cover with a UCSDish blue color scheme, and the abstract and a graduation photo on the back cover.

When you are all finished, Lulu creates a page where you or anyone else can buy copies of the book. (You have the option of keeping this private, so that only people you share it with can find it.) Then you can buy as many copies as you want to keep or give away, and you can also send the link to your parents if they want to buy lots of copies for all the relatives. (In this case, Lulu’s “revenue” option may be useful, where you select an amount to add to the price of the book, which Lulu passes along to you after each sale. The page remains up indefinitely if you want more copies later.

If you want to see what a finished product looks like, Nate Eldredge’s thesis Lulu page is located at http://www.lulu.com/content/7559872.

The book turned out quite nice looking, with quality and appearance comparable to commercially published math books. And they were only $15.46 per copy (plus tax and shipping). Overall that is a vast improvement over UMI.

Also, Nate uploaded the template as a Lulu project. It can be found at http://www.lulu.com/content/7686303.

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COLLEGE OF LIBERAL ARTS AND SCIENCES

Department of Mathematics

Thesis formatting, introduction.

If you write a Ph.D. thesis, you have to follow the  specifications  of the graduate school.

Additional information and answers to frequently asked questions can be found the graduate school’s Doctoral Degree Programs page.

A thesis in mathematics is invariably written in some form of LaTeX. It is usually quite a large LaTeX project, so it should not be your first attempt at typesetting. This implies that you should have typed a couple articles, quizzes, homeworks or exams in LaTeX before embarking on this. Below, two options have been created that conform to the guidelines set forth by the graduate school. The first is a minimal option that builds on the familiar book class that comes standard with any LaTeX distribution, while the second is a class file to be used in place of the book class, but contains extra content not suitable for all users. You may choose the option that works best in your case.

Below are a few of the well-done thesis variants from our department.

• Thesis class by Waseet Kazmi – 2023
• Thesis class by Ben Salisbury – 2012
• Thesis class by Marc Corluy – 2000

After unzipping put files into  one  directory. Some browsers (e.g. Safari on the Macs in the department) will put the files on your desktop. In this case create a new folder and put them all in there. In any case, make this move before you start compiling, because LaTeX generates a multitude of files when compiling and your desktop will turn into a (more?) disorderly mess.

Also make sure that the extensions are preserved. Some browsers have a tendency to slap on “.txt” at the end.

Open a text editor or a dedicated LaTeX editor,  such as TeXShop  (installed on department Macs).  When you are typing LaTeX code, it is usually clearer to use a fixed width font so that you have a clear view of your indentations and matrices (should there be any). In TeXShop, a good choice is “Courier Bold 14pts”. This font also has different characters for “|” and lowercase L. This is particularly important if you are trying to typeset tables where both “|” and lowercase L are used in the declaration.

You will now have to open some of the files that you downloaded and edit them. Here are descriptions of the set of files prepared by Ben Salisbury, listed (as best as possible) in order of priority.

• macros.tex  This file is the heart of your personalization. If you have been using LaTeX for your other manuscripts and have developed your own set of user-defined commands, then you should put them in this file. If you are importing text into one of the later files from an older LaTeX file with predefined commands, you will want your personal macros to be loaded already before fumbling with LaTeX error messages.

so those who prefer to use, say,

• thesis.tex  Lines 8 through 17 of this file require the user to input their personal data; i.e., name, degrees, year of graduation, advisory committee, and title. Further down in the file, you’ll notice the command \input{ch1.tex} . This imports the text from  ch1.tex  to the current position in this file. By copying the command and changing ch1 to ch2 (and so on), you will be able to link all chapters of your work to this file. Essentially, this file is the glue that holds the whole project together. This is also the file on which the TeX engine is run to obtain the desired output.
• abstract.tex ,  acknowledgments.tex , and  ch1.tex  should be self-explanatory. Of course, you should have more than one chapter to their thesis. The challenge of creating LaTeX files for the subsequent chapters is left to the user. Good luck!
• thesis.bib  This is a standard BibTeX file to be used as the source for your bibliography output. This may take some time to learn, so the file comes preloaded with a sample  .bib  file. Your best bet is find some literature on BibTeX to tackle this beast. Of course, one could simply replace the bibligraphy declarations in the  thesis.tex  with a manual bibliography, as Marc Corluy does in his setup below. To each his own.
• frontmatter.tex  Simply put: don’t touch it. If you need to make changes here, you should probably consider using Marc Corluy’s template (unless you are familiar enough to make the appropriate changes).

Here are comments on the files prepared by Marc Corluy.

• bibliography.tex  is not your first concern. The references that are listed in there are there to give you an idea about the exact format in which a book or article should be entered into this file.
• chapter1.tex ,  chapter2.tex , and  introchapter.tex  are almost empty; they are merely there to show you how to use titles and sections.
• The file  definitions.tex  you can completely ignore if you want to. It contains (re)definitions of some symbols and a fairly long list of basic mathematical symbols and functions. It can be handy to get a certain feel for how to use “def” in LaTeX and you can also add whatever you end up using often in your thesis.
• Most of the static data (title of the thesis, your previous degrees, your advisors, acknowledgment etc.) are entered in  front_matter.tex . The comments in this file will explain you what to put where.
• If you want to explain some of the notation that you use in your thesis, you should do so in notationpage.tex . It is technically part of the front matter of the thesis, but it is a separate file because this is probably the only part of the front matter data that changes as the thesis evolves.
• You will probably not change much to  settings.tex . This file loads a lot of the extensions to LaTeX and defines the elements of the  amsthm.sty  package, as is explained in the comments in  settings.tex .
• As you can guess,  thesis.tex  is the file where it all comes together. The includeonly command will allow you to compile only parts of your thesis if you prefer to do so. Note that you should compile the thesis twice to make sure that all the labels are set correctly.
• In principle, you should never change anything to  uconnthesis.cls .

Write your thesis. Good Luck.

Senior Thesis

This page is for Undergraduate Senior Theses.  For Ph.D. Theses, see here .

A senior thesis is required by the Mathematics concentration to be a candidate for graduation with the distinction of High or Highest honors in Mathematics. See the document ‘ Honors in Mathematics ’ for more information about honors recommendations and about finding a topic and advisor for your thesis. With regards to topics and advisors: The document ‘ Faculty research areas ’ lists the research interests of current members of the Math Department.

So that Math Department senior theses can more easily benefit other undergraduate, we would like to exhibit more senior theses online (while all theses are available through Harvard University Archives, it would be more convenient to have them online). It is absolutely voluntary, but if you decide to give us your permission, please send an electronic version of your thesis to cindy@math. The format can be in order of preference: DVI, PS, PDF. In the case of submitting a DVI format, make sure to include all EPS figures. You can also submit Latex or MS word source files.

If you are looking for information and advice from students and faculty about writing a senior thesis, look at this document. It was compiled from comments of students and faculty in preparation for, and during, an information session. Let Wes Cain ([email protected]) know if you have any questions not addressed in the document.

Universität Bonn

Preparation of the Final Thesis

The mathematics degree programs conclude with a Bachelor's or Master's thesis, in which independent work on a mathematical topic is to be demonstrated. The Examination Board has compiled the most important requirements for theses and some assessment criteria as guidelines.

• Please read the document carefully before you register your thesis.
• When registering the thesis, you confirm with your signature that you have taken note of the requirements in the document.

The teacher training programs also end with a final thesis. This can be completed in the subject mathematics.

Rules for Theses in the Subject-Specific Study Programs

Here you will find the regulations for registering and submitting final theses that apply to both mathematics programs. Specific deadlines and rules are listed under the respective degree program.

As a rule, students find a supervisor for their thesis on their own initiative.

• Every professor of mathematics in Bonn can of course assign topics for theses.
• Many other doctoral lecturers at Bonn Mathematics have been appointed by the Examination Board to supervise theses. You can enquire about this with the person concerned.
• One of the two reviewers must always be a professor of mathematics at Bonn University.
• If you have not found a supervisor yourself, you can also have one assigned to you by the Examination Board . In this case, please contact the Bachelor-Master Office Mathematics.

The thesis must be registered using the form Registration of the Thesis .The form must be signed by both you and the supervisor of the thesis.

• The form must state the topic of the thesis and your first supervisor.
• You also confirm that you have taken note of the requirements for the final theses of your degree program.
• At the same time, you will be registered for the seminar accompanying your thesis.
• The registration form must be submitted to the Bachelor-Master Office Mathematics immediately after the topic has been assigned and within four weeks of the supervisor's signature.
• If the registration form is received in February or August, the thesis can still be assessed in the semester in which it is submitted.
• For the accompanying thesis seminar you earn 6 credit points. It is registered for the semester in which your thesis is due for submission.
• During the time you are working on your thesis, there are usually three presentations in the thesis seminar on the topic of the thesis and the results achieved.
• The examination of the thesis seminar consists of a graded (final) presentation, which should be held shortly before or shortly after the submission of the thesis. 
• The day on which you give the graded presentation is an examination date and is therefore relevant for your degree.
• Therefore, please make sure that the presentation takes place before the end of the semester in which you wish to graduate.
• The deadline for submitting your thesis is calculated from the signature date of your supervisor plus the working time.
• You can see the submission date of your thesis in BASIS.
• The deadline for submitting your thesis is strict. If you submit the thesis after this date, it will be failed.
• Please note that you are responsible for meeting the submission deadline. Your supervisors are not necessarily aware of your submission deadline, and in no case could they change the deadline for you, as this is set by the examination regulations.
• In the event of illness , the deadline can be extended by up to six weeks.

The thesis must be submitted on time in the required number of copies together with the form Submission of the Thesis at the Bachelor-Master Office Mathematics . On the submission form, you confirm that you have written the paper independently and have not used any sources or aids other than those specified and that you have indicated any quotations.

Requirements:

• DIN A4, printed on both sides, with cover page
• in a bound version (no spiral bindings please!)
• If programming code or similar is available, it must be attached to each copy of the work on a CD or a USB stick that is as flat as possible (do not send it by e-mail). The CD or stick must be glued to the last page of a copy.
• A single copy of the submission form must be submitted separately.

Options for submitting the thesis:

• personal delivery during office hours
• personal delivery after making an appointment outside office hours
• by post to the Bachelor-Master Office Mathematics The date of the postmark is decisive for the submission.

The thesis is evaluated by two assessors.

• The first assessor is the person who provided the topic of the thesis.
• The second assessor must be proposed by you when you submit your thesis. You are therefore responsible for finding a suitable second reviewer. On request, the supervisor can of course help you with this.
• Both reviewers must be noted on the title page of the thesis (see templates for the title page).

As a rule, the candidate is notified of the thesis' evaluation six to eight weeks after the submission date.

Bachelor's Thesis (B.Sc. Mathematik)

• The topic of the Bachelor's thesis is usually assigned towards the end of the fifth semester.
• You need to have earned at leat 90 credit points in order to register the Bachelor's thesis.

The working period of a Bachelor's thesis is five months.

• The Bachelor's thesis is estimated to require a workload of 360 hours.
• Therefore it earns 12 credit points.

The text part of the Bachelor's thesis must be between 5 and 50 pages long.

• Deviations from this require the approval of the Examination Board.
• In this case, please obtain the consent of both your advisors.
• Then send an application by e-mail to the Bachelor-Master Office Mathematics .

The language of the Bachelor's degree program is German. You can write your Bachelor's thesis in English if

• your supervisor agrees with it and
• the thesis contains a summary in German.

There is a coursework for the Bachelor's thesis seminar, the training in subject-specific literature research . It will be noted in BASIS when you register your Bachelor's thesis and it is a prerequisite for passing the Bachelor's thesis seminar.

The training courses are offered by the University and State Library in the form of a one-off two-hour course. The course imparts knowledge that is very useful for academic work, especially when writing a Bachelor's thesis, for example the use of the relevant academic online archives.

• The courses are held in the MNL departmental library in the training room on the 1st floor.
• Usually three dates are offered every semester, each on a Monday or Wednesday from 16.15 to 18.00 hrs.
• You can register for a date via an online form.

After you have taken part in a course, we will enter the coursework as passed in BASIS.

• You must complete this training shortly before or during the time you are working on your Bachelor's thesis.

The title page of your Bachelor's thesis must be agreed with your supervisor.

• In particular, make sure that you name the correct institute to which your supervisor belongs.
• Please use our LaTeX-template for the title page of your Bachelor's thesis.

The submission deadline for the Bachelor's thesis is 5 months after the date on which the supervisor signed the application.

• Three copies of the Bachelor's thesis must be submitted.

Master's Thesis (M.Sc. Mathematics)

• The topic of the Master's thesis is usually assigned towards the end of the second semester.
• You need to have earned at leat 30 credit points in order to register the Master's thesis.

The working period of a Master's thesis is twelve months.

• The Master's thesis is estimated to require a workload of 900 hours.
• Therefore it earns 30 credit points.

The text part of the Master's thesis must be between 10 and 100 pages long.

The language of the Master's degree program is English. You can write your Master's thesis in German if

• the thesis contains a summary in English.

The title page of your Master's thesis must be agreed with your supervisor.

• Please use our LaTeX-template for the title page of your Master's thesis.

The submission deadline for the Master's thesis is 12 months after the date on which the supervisor signed the application.

• Four copies of the Master's thesis must be submitted. One copy will be made available to the Mathematics Library.

If you would like to apply for a PhD position at BIGS Mathematics you should find out about the application process at the beginning of the third Master's semester.

Reimbursement of the Printing Costs for the Thesis

The printing costs for the required copies of your thesis can be reimbursed upon application. This also applies to theses in the teacher training programs that were written in mathematics.

• Please fill out the application form and hand it in at the Bachelor-Master Office Mathematics.
• The enclosed original receipt must show the number of copies printed.
• Please attach the receipts to the separately printed page 2 of the form using a glue stick.

Please submit the form promptly, as the original receipts are only valid for 6 months.

Examination Office Mathematics

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Definition of thesis

Did you know.

In high school, college, or graduate school, students often have to write a thesis on a topic in their major field of study. In many fields, a final thesis is the biggest challenge involved in getting a master's degree, and the same is true for students studying for a Ph.D. (a Ph.D. thesis is often called a dissertation ). But a thesis may also be an idea; so in the course of the paper the student may put forth several theses (notice the plural form) and attempt to prove them.

Examples of thesis in a Sentence

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'thesis.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

in sense 3, Middle English, lowering of the voice, from Late Latin & Greek; Late Latin, from Greek, downbeat, more important part of a foot, literally, act of laying down; in other senses, Latin, from Greek, literally, act of laying down, from tithenai to put, lay down — more at do

14th century, in the meaning defined at sense 3a(1)

Dictionary Entries Near thesis

the sins of the fathers are visited upon the children

thesis novel

Cite this Entry

“Thesis.” Merriam-Webster.com Dictionary , Merriam-Webster, https://www.merriam-webster.com/dictionary/thesis. Accessed 28 Aug. 2024.

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Thesis and Completing your Studies in Mathematics

In order to successfully complete a Bachelor's or Master's degree program in the area of Mathematics, students must write a scientific work: the Bachelor’s thesis or Master's thesis. Here, you will find an overview of everything you need to know, from planning to submission:

General Information

Registration, when and where.

It is possible to register your thesis on the 1st and 15th of each month. 

All final theses starting from  1st February 2024 onwards in the PP Mathematics at the School of Computation, Information and Technology will be managed via the CIT portal .

Once you have found a topic and a supervising chair for your thesis, you will be registered by the supervising chair . You will receive an e-mail asking you to confirm your thesis registration. Only after you have confirmed your registration the Academic Programmes Office will be able to check the admission requirements and you will receive an email confirming your binding registration for your thesis.

For more information, see  Thesis and Completing your Studies .

Further documents?

If you have completed extracurricular activities or a stay abroad during your studies, these can be included in the Diploma Supplement. To do this, we need the  Route Card for the Diploma Supplement   by the end of your studies at the latest. Please send the completed form as a PDF or photo/scan (readable) to  bachelor(at)ma.tum.de  or  master(at)ma.tum.de . We recommend you to hand in the Route Card when registering your thesis or shortly afterwards. Please also note the Information on the Diploma Supplement .

For more information, see  Thesis and Completing your Studies

Note: The  Diploma Supplement  is an English-language supplement to the university diploma and describes the qualifications linked to the study program. Under the heading “Additional Information” in this document, you can request the incorporation of specific details of extracurricular activities completed within the framework of your degree course.

Composition

The thesis can be written in German or English language. The Bachelor's thesis muss be prefaced with an abstract in the other language, not the one in which it is written.

Formal considerations

Cover page and page 1

Here you indicate the topic of the work as well as your name and that of the supervisor. In addition, you indicate the date of submission (see example).

Example of a cover page

Here you make the following declaration: 

“I hereby declare that this thesis is my own work and that no other sources have been used except those clearly indicated and referenced.” (Place, date, signature either on a tablet or as a scan of your original signature).

If you do not wish to use a digital signature, you may alternatively submit a separate page with the declaration and your original signature at the Infopoint.

Change of title

Please write an e-mail containing the new thesis title to  bachelor(at)ma.tum.de  or  master(at)ma.tum.de  and CC your supervisor and co-supervisor.

Submisson and extension of theses starting until and including 15.01.2024

Digital submission.

The Bachelor's or Master's thesis has to be submitted digitally. Please submit the thesis as a PDF file to  bachelor(at)ma.tum.de  or  master(at)ma.tum.de   within the deadline . If you have to hand in code or other files, please e-mail all files collected in a zip folder. Printed copies and USB sticks will no longer be accepted.

Should the submission date fall on a weekend or a public holiday, submission on the subsequent workday is also possible. Theses can of course also be submitted prior to the planned submission date. 

In the event that you need more time to work on your thesis, you must submit an application to  bachelor(at)ma.tum.de  or  master(at)ma.tum.de  for an extension, at least seven days prior to the planned submission date. This application must have been signed by your thesis supervisor (or you have to send the consent of the supervisor in electronic form). In the event of a second extension, the Chair of the Examination Board must sign the application as well as the thesis supervisor.

Bachelor's Thesis: Application for an extension Master's Thesis: Application for an extension

Submisson and extension of theses starting from 01.02.2024 onwards

Theses registered from 01.02.2024 onwards are managed entirely via the CIT portal . This portal is also used for submission within the deadline (including all required files, such as codes). If necessary, you can also apply for an extension of the submission deadline.

Tools and tips

The typesetting system  LaTeX  is the standard program worldwide for the compilation of theses that contain mathematical formulas. It is recommended that you familiarize yourself with LaTeX as early as possible during the course of your studies. It is a good exercise to prepare sheets for seminar presentations using LaTeX. 

You can find further information, templates and helpful advice on our  LaTeX info page .

Corporate design and use of  TUM logos

Thesis Templates for LaTeX

LaTeX-Template Bachelor / Master

The  TUM Library  does not only offer outstanding access to a wide range of books, newspapers, and electronic media, it also offers courses on, for example, bibliographical research and how to correctly cite works. 

Please also note subject-specific practices when citing works.

Further seminar papers and tools specific to mathematics

For licensing and contractual reasons, some of these databases are only accessible via domains belonging to the TUM Departments of Mathematics and/or Informatics. Please address queries where applicable to your supervisor or the TUM Library:

• MathSciNet  – Mathematical reviews on the web
• JADE  – Journal Articles Database
• ERAM  – Electronic Research Archive for Mathematics
• Online database at  Zentralblatt MATH

English theses

The  English Writing Center  offers all TUM members free one-to-one advice on writing English texts and helps you to enhance your writing skills.

Any questions?

For questions relating to the content of your Bachelor's or Master's thesis, please contact your thesis supervisor as defined in the General Academic and Examination Regulations (APSO), co-supervisor or the Student Advisory Office responsible.

Bachelor's Thesis Details

When to start.

Do you have at least 8 credits in Advanced Courses? Then it is the right moment to commence your Bachelor’s thesis. By the eighth semester of enrollment in your current degree program, at the latest, you must commence your thesis as long as there are no reasonable grounds preventing you from doing so in accordance with section 10 (6) of the  APSO .

Time frame & length

You have three months in which to complete your Bachelor’s thesis. This period begins on the date of registration. During this period, you should spend an average of at least 30 hours per week on the Bachelor's thesis – an effort equivalent to 12 credits.

The Bachelor’s thesis should not exceed 35 pages.

Choice of topic

In order to reduce the time needed to familiarize yourself with the topic, it is recommended to choose a topic for your Bachelor's thesis which corresponds to the theme of the Advanced Seminar taken.

Examiner and assessment

The Bachelor’s thesis must be evaluated by someone who is authorized to do so (thesis supervisor as defined in the APSO) at the TUM School of CIT. You will find an overview of other eligible persons outside the School of CIT in the list below. It is the written work that is assessed. The talk you give concerning the content does not affect the grading.

Persons outside the School of CIT who are authorized to examine theses

Master's Thesis Details

You have six months to complete your Master’s thesis. This period begins on the date of registration. You normally complete the Master’s thesis in the fourth semester of your Master’s program after you have fulfilled all other academic and exam requirements.

Examiners and assessment

The Master’s thesis must be approved and evaluated by someone who is authorized to do so (thesis supervisor as defined in the APSO) at the TUM School of CIT. You will find an overview of other eligible persons outside the School of CIT in the list below:

Completing your Studies

Release of final certificate.

Once you have completed all the requirements for your degree, we will contact you by email and ask for the approval to issue your diploma certificate.

Graduation documents and preliminary certificates

After you have given us the approval for the generating of your diploma certificate, your graduation documents will be generated within 4 - 6 weeks at the Graduation Office and Academic Records Campus Garching . You will be notified by post as soon as your certificate has been issued. Please make sure that your current study address in TUMonline is up to date.

If required, you can also apply to the Graduation Office and Academic Records Campus Garching for a preliminary certificate .

Transition Bachelor – Master

If you have applied for a consecutive mathematics Master's program at our school after completing your TUM mathematics Bachelor's degree, please let us know (at bachelor(at)ma.tum.de ). It is possible to forward your Bachelor's degree to the Admissions and Enrollment Office for enrollment (not for the application!). The graduation documents are therefore not necessary for enrollment. A green checkmark will then appear in the online application portal for your degree certificate and diploma ( Application Status ). Please note that it may take a few days until the documents are updated in the portal. If you do not see these two green check marks one week before the enrollment deadline, please contact bachelor(at)ma.tum.de as soon as possible.

Diploma Supplement

If you have completed extracurricular activities or a stay abroad during your studies, these can be included in the Diploma Supplement. To do this, we need the  Route Card for the Diploma Supplement   by the end of your studies at the latest. Please send the completed form as a PDF or photo/scan (readable) to  bachelor(at)ma.tum.de  or  master(at)ma.tum.de . Please also note the Information on the Diploma Supplement .

Please find more information under  graduation .

Guidelines for writing a thesis

These guidelines are intended for students writing a thesis or project report for a  Third Year Project Course ,  Honours year  or  Postgraduate Coursework Project . Postgraduate research students should see  Information about Research Theses  for postgraduate research students.

Before you start your Honours or Project year, you should speak to members of staff about possible thesis topics. Find out who works in the areas that you are interested in and who you find it easy to talk mathematics with. If at all possible, settle on a topic and supervisor before the start of the first semester of your Honours or Project year.

Most students see their supervisor about once a week, although this is usually open to negotiation between the student and the supervisor. Even if you haven't done much between visits it is a good idea to have a regular chat so that your supervisor can keep track of how you are going. You can expect your supervisor to:

• Help you select - and modify - your topic.
• Direct you to useful references on your topic.
• Help explain difficult points.
• Provide feedback on the direction of your research.
• Read and comment on drafts of your thesis.
• Help prepare you for your talk.
• Give general course advice.

Your thesis or project report is an overview of what you have been studying in your Honours or Project year. Write it as if you were trying to explain the area of mathematics or statistics that you have been looking at to a fellow student.

• Include an introduction that explains what the project is all about, and what its contents are. (It is sometimes better to leave writing this part to the end!) For many reports, a conclusion or summary is appropriate.
• Your thesis should be a coherent, self-contained piece of work.
• Your writing should conform to the highest standards of English. Aim at clarity, precision and correct grammar. Start sentences with capital letters and end them with full-stops. Don't start sentences with a symbol.
• Take great care with bibliographic referencing. Wherever some material has an external source, this should be clear to the reader. Don't just write in the introduction: 'This report contains material from [1],[2] and [3]' - give the references for the material wherever it is used. Don't gratuitously pad your reference list with references that are not referred to in the text. Check current journals for acceptable referencing styles.
• Be careful not to plagiarise. What constitutes plagiarism is perhaps a little different in mathematics and statistics compared to some other subjects since there is a limit to how different you may be able to make a proof (at least in its basic structure). We do, however, expect the report to be written in your own words. A basic rule is: if you put a fact or an idea in your report which is not your own, the reader should be able to tell where you got this fact or idea.
• The University has  policies on academic honesty and plagiarism  which all students should familiarise themselves with.

Generally, mathematics reports and theses are almost always typed in LaTeX. If you are going to type it yourself, you should allow a certain amount of time to become familiar with this software. Indeed, starting to learn LaTeX well before you actually want to write is a very good idea.

You should not underestimate the time it takes to produce a polished document. You will almost certainly need several drafts. It is very difficult to concentrate on getting the mathematics, spelling, grammar, layout, etc., all correct at once. Try getting another student to proofread what you have written - from their different viewpoint they may pick up on lots of things that you can't see.

P R Halmos (1970) in  How to write mathematics, Enseignement Math.  ((2) 16, 123-152) has the following advice: "The basic problem in writing mathematics is the same as in writing biology, writing a novel, or writing directions for assembling a harpsichord: the problem is to communicate an idea. To do so, and to do it clearly:

• you must have something to say (i.e., some ideas), and you must have someone to say it to (i.e., an audience)
• you must organize what you want to say, and you must arrange it in the order you want it said in
• you must write it, rewrite it, and re-rewrite it several times
• and you must be willing to think hard about and work hard on mechanical details such as diction, notation, and punctuation.

That's all there is to it."

His other advice includes:

• Say something: "To have something to say is by far the most important ingredient of good exposition---so much so that if the idea is important enough, the work has a chance to be immortal even if it is confusingly misorganized and awkwardly expressed..... To get by one the first principle alone is, however, only rarely possible and never desirable."
• Audience: "The second principle of good writing is to write for someone. When you decide to write something, ask yourself who it is that you want to reach." Your broad audience will be fellow Masters and Honours students, who may not be experts in your thesis topic. "The author must anticipate and avoid the reader's difficulties. As he(/she) writes, he(/she) must keep trying to imagine what in the words being written may tend to mislead the reader, and what will set him(/her) right."
• Organise: "The main contribution that an expository writer can make is to organize and arrange the material so as to minimize the resistance and maximize the insight of the reader and keep him(/her) on the track with no unintended distractions". 
• Think about the alphabet: "Once you have some kind of plan of organization, an outline, which may not be a fine one but is the best you can do, you are almost ready to start writing. The only other thing I would recommend that you do first is to invest an hour or two of thought in the alphabet; you'll find it saves many headaches later. The letters that are used to denote the concepts you'll discuss are worthy of thought and careful design. A good, consistent notation can be a tremendous help".
• Write in spirals: "The best way to start writing, perhaps the only way, is to write on the spiral plan. According to the spiral plan the chapters get written in the order 1,2,1,2,3,1,2,3,4 etc. You think you know how to write Chapter 1, but after you've done it and gone on to Chapter 2, you'll realize that you could have done a better job on Chapter 2 if you had done Chapter 1 differently. There is no help for it but to go back, do Chapter 1 differently, do a better job on Chapter 2, and then dive into Chapter 3... Chapter 3 will show up the weaknesses of Chapters 1 and 2".
• Write good English: "Good English style implies correct grammar, correct choice of words, correct punctuation, and, perhaps above all, common sense."

More information on how to write mathematics:

• Lee, K. A guide to writing mathematics
• Lee, K. Some notes on writing mathematics 
• Jackson, M. Some notes on writing in mathematics
• Reiter, A. Writing a research paper in mathematics
• Honours thesis
• Postgraduate Coursework Project
• Third Year Project Courses

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What kind of definitions need be introduced in a PhD thesis? [closed]

For all the terminology in mathematics, I am not sure where to draw a line between those which need to be introduced in a PhD thesis and those which do not. For example, I suppose that in a PhD thesis, no one will bother to give the definition of group , or normal subgroup , etc. but probably commutators as it can be defined in two different ways, namely $x^{-1}y^{-1}xy$ and $xyx^{-1}y^{-1}$. For braid group one probably will write down the definition anyway, even though it is well known among topologists. I am not sure about some terminologies such as the lower central series : does it need to be introduced?

Where do we draw the line?

• article-writing

• $\begingroup$ Yes, lower and upper central series, and commutator series are usually defined in a PhD thesis - just to fix the notations (the index differs sometimes). $\endgroup$ –  Dietrich Burde Commented Nov 27, 2014 at 8:43
• $\begingroup$ Thanks @DietrichBurde, actually I am asking the guideline generally; how do I know if a terminology need to be introduced? $\endgroup$ –  Zuriel Commented Nov 27, 2014 at 8:44
• 1 $\begingroup$ Rough guideline: Presumably you have a good sense of what’s usual in papers in your area; be a bit more generous with definitions than that. (This is in addition to specifying conventions and notation.) $\endgroup$ –  Brian M. Scott Commented Nov 27, 2014 at 20:01
• 1 $\begingroup$ You have a thesis advisor presumably. Let her be the judge. $\endgroup$ –  Lubin Commented Nov 28, 2014 at 1:56
• $\begingroup$ @DietrichBurde, do you think it is necessary to define Lie algebras and free Lie algebras? $\endgroup$ –  Zuriel Commented Feb 9, 2015 at 14:38

3 Answers 3

One of the professors I was working with during my PhD and that has the reputation to write deep articles in a very accessible way once gave me that advice:

"A PhD thesis is not an article. This is one of the few occasions in your career where you are given plenty of space to write everything you want to say. Take that space to add many examples and remarks. Also, a thesis, in addition to the presentation of new important results, is an exposition of the current state of arts of your domain. Explain all definitions and concepts clearly. Think about you at the beginning of your PhD, when you were struggling to understand articles, decyphering what is "clear" or "well-known". You wished you had a place where you could find a clear exposure of these facts. Your thesis should be that place".

I hope it helps.

• $\begingroup$ This is very nice. $\endgroup$ –  Lubin Commented Nov 28, 2014 at 1:55

As with any piece of mathematical writing, include definitions if you think it is reasonable that some of your readers will not already know them. Additionally, if you think that your readers will know definitions, but you are aware of multiple conventions, do your readers the kindness of stating which convention you use. If you are unaware of multiple conventions, I suggest not worrying about it.

A definition can be also used to introduce a consistent notation.

For instance, if the thesis deals with different concepts of differentiation, then a definition can be used to fix the notations, like, e.g. $f'(x;h)$ is the directional derivative of $f$ at $x$ in direction $h$, $\partial_{x_i}f(x)$ is a partial derivative.

Not the answer you're looking for? Browse other questions tagged article-writing publishing .

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Theory, Thesis, Hypothesis and the mysterious Theorem

lately I have been thinking about the terms theory, thesis, hypothesis and theorem. I am quite sure about the differences between a thesis and a hypothesis, but I did not really get what a theorem is. I would like to ask you to confirm my definition of each term or don' t. If you disagree with my definition, please explain why and give - if possible - a good example.

As an example I will use the axiom "Nothing is faster than light" of the Theory of Relativity.

Thesis : As far as I have figured out, a thesis is an assertion which a controversy is immanent to. So it needs a argumentative reasoning.

My first question, in reference to my example, is if every axiom is implicitly a thesis or not.

I am not sure about it, because if I took the axiom from the example, I would not know if there is any controversy about this assertion or if it is just an undisputed assertion, although there could be a controversy, because nobody can know if there is not something faster than light. On the other hand, if I have the assertion "There is a God", its clear to me that there will be a controversy. So it must be a thesis.

Further on I will assume the example axiom to be a thesis for further illustration.

Hypothesis : A hypothesis is a derived form of a thesis. It asserts a correlation between - at least - two factors (where a thesis is simply an assertion).

So in reference to the example I could derive the hypothesis "If there was something faster than light, then there would be a God" from my thesis "Nothing is faster than light". It asserts a correlation between the factors "speed of light" and "existence of a God" (although there is no causal relationship).

Theory: A theory is an abstract concept which tries to explain a discipline of reality. It consists of axioms/theses.

Theorem: This is something that I was not really able to figure out. I found a pattern in theoremes: It always seems to be based on some theory and tries to solve some paradoxon or other problem the theory has, but it does not change the theory at all. It is some lego that is put on the theory to fill a hole.

I don' t know if there is any truth in what I have written about the theoreme.

So I hope you can help me understanding :)

• terminology

• The words have different meaning in difference contexts, i.e. you don't prove theorems in physics you prove theories but a theory in physics is more like a conjecture in mathematics. A theorem is something that is proved deductively using logical reasoning or inference (think about what you do in a formal logical system like propositional logic). Mathematical theorems, like the fundamental theorem of arithmetic, are theorems because they can be proved in a completely deductive way. Physical laws are not proved deductively, they are proved inductively through observation and experiment. –  Not_Here Commented Jul 29, 2017 at 10:42
• From wikipedia's article on theorem: "In light of the requirement that theorems be proved, the concept of a theorem is fundamentally deductive, in contrast to the notion of a scientific law, which is experimental." In mathematics, conjectures are a lot more like scientific laws than theorems because they are things that we do not have a deductive proof for yet, but every test we've ever done to the conjecture came up positive. Consider Goldbach's conjecture, it is a conjecture because it doesn't have a proof yet, but we have yet to find a single counterexample, despite massive testing. –  Not_Here Commented Jul 29, 2017 at 10:44
• The biggest issue you're having, I think, is that you're mixing how the words are used in science and how they're used in math. Obviously there is over lap but the words have different meanings when they're used very strictly in those two contexts. For example, your definition of theory (besides the use of the term axioms because those also have different meanings in different contexts) is correct when applied to science but theory has a different definition in mathematical logic where it's a set of axioms and theorems in some formal language. –  Not_Here Commented Jul 29, 2017 at 10:51
• See if any of these definitions help you theorem , axiom , scientific hypotheses and scientific theories , mathematical conjecture , general statement of hypothesis that also touches on how its specifically used in mathematics . –  Not_Here Commented Jul 29, 2017 at 10:55

The biggest trouble that you will face when thinking about these ideas is that you are mixing terminology from two distinct fields into one. Some of those words are used very differently in science than they are in mathematics. It can become even more confusing when you consider how much math is used in science, but an explanation of how the words are used in their specific contexts will help illuminate the delineating line.

In mathematics, "thesis", "hypothesis", and "conjecture" are all used synonymously. From Wolfram's Mathworld:

Hypothesis: "A hypothesis is a proposition that is consistent with known data, but has been neither verified nor shown to be false." "In general mathematical usage, 'hypothesis' is roughly synonymous with 'conjecture.'" Conjecture: "A proposition which is consistent with known data, but has neither been verified nor shown to be false. It is synonymous with hypothesis."

Additionally, if you go to the disambiguation of the word "thesis" on wikipedia you see that in the subjects of mathematics and logic it links to "hypothesis" and "conjecture" as well. An example of a mathematical thesis is the Church-Turing thesis which, as you can see, is also sometimes called the Church-Turing conjecture and is described in that article as being a hypothesis. The reason that the Church-Turing thesis is a thesis is because it tries to take an informal idea (the idea of an algorithm) and give it a precise mathematical statement. Due to the fact that it starts with an informal idea, there isn't a purely deductive way to prove that the idea is true, therefore it's left open as a hypothesis and would be proven untrue if a counter example is shown.

As such, mathematical conjectures, theses, and hypotheses are statements in mathematics that seem probable and no counter example has yet been shown. This means that conjectures have yet to be proven , which delineates them from theorems.

A theorem is something that is not a conjecture, it is something that has been proven true. From Mathworld:

Theorem: "A theorem is a statement that can be demonstrated to be true by accepted mathematical operations and arguments. In general, a theorem is an embodiment of some general principle that makes it part of a larger theory. The process of showing a theorem to be correct is called a proof."

Examples of theorems are proven mathematical statements, things like the fundamental theorems of arithmetic , algebra , and calculus . Other, much simpler theorems, are things like the Pythagorean theorem . The picture of a theorem as something that solves a paradox or other problem is incorrect, a theorem is just a provably true statement. The Pythagorean theorem doesn't resolve a paradox in geometry, it is just a statement that has to be true, is provable, given the initial rules of geometry (the axioms).

Those are how the words are used in mathematics alone and in science they are sometimes used very differently. One important thing to understand is that science does not deal with theorems, scientific theories don't prove theorems. This is because science relies on inductive and abductive reasoning to learn about the world through empirical observation. A scientific theory is a general description of the world that is testable and has withstood repeated testing. In this way, they're usually made up out of scientific laws .

Scott Aaronson , a quantum information scientist who works on both fields, has highlighted the differences in the terminology on multiple occasions:

"I've learned from working in quantum information that there's a difference in terminology between fields. What mathematicians and computer scientists call a conjecture is typically what physicists would call a law." "I think my word is 'theorem'. It's something that you say is true and then you explain why it's true and then you put a box."

The context for the second quote is that Leonard Susskind asked Aaronson to explain a word from his mathematical background that people with a physics background might not understand or use in the same way. The reason everyone laughed is because the other physicists and computer scientists in the room understood how tongue in cheek Aaronson's pick for the word was: physics doesn't deal with theorems, in a mathematical sense, it deals with conjectures. That's why Susskind sarcastically says "A theorem, what's that?" And of course the "box" comment is a reference to what's put at the end of a proof of a theorem .

Ultimately, theorems are things that are deductively proven and as such exist in mathematics and logic. Theorems are used in science as well, you can use the Pythagorean theorem to help you solve a mechanics problem, but science doesn't prove theorems. Science tries to create theoretical models that help explain physical phenomena and those models can always be revised via new information. So if you are trying to apply the word theorem to a physical theory you are going to fail, the only parts of the physical theory that are theorems are the purely mathematical parts.

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Mathematics PhD theses

A selection of Mathematics PhD thesis titles is listed below, some of which are available online:

2023   2022   2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991

Reham Alahmadi - Asymptotic Study of Toeplitz Determinants with Fisher-Hartwig Symbols and Their Double-Scaling Limits

Anne Sophie Rojahn –  Localised adaptive Particle Filters for large scale operational NWP model

Melanie Kobras –  Low order models of storm track variability

Ed Clark –  Vectorial Variational Problems in L∞ and Applications to Data Assimilation

Katerina Christou – Modelling PDEs in Population Dynamics using Fixed and Moving Meshes  

Chiara Cecilia Maiocchi –  Unstable Periodic Orbits: a language to interpret the complexity of chaotic systems

Samuel R Harrison – Stalactite Inspired Thin Film Flow

Elena Saggioro – Causal network approaches for the study of sub-seasonal to seasonal variability and predictability

Cathie A Wells – Reformulating aircraft routing algorithms to reduce fuel burn and thus CO 2 emissions  

Jennifer E. Israelsson –  The spatial statistical distribution for multiple rainfall intensities over Ghana

Giulia Carigi –  Ergodic properties and response theory for a stochastic two-layer model of geophysical fluid dynamics

André Macedo –  Local-global principles for norms

Tsz Yan Leung  –  Weather Predictability: Some Theoretical Considerations

Jehan Alswaihli –  Iteration of Inverse Problems and Data Assimilation Techniques for Neural Field Equations

Jemima M Tabeart –  On the treatment of correlated observation errors in data assimilation

Chris Davies –  Computer Simulation Studies of Dynamics and Self-Assembly Behaviour of Charged Polymer Systems

Birzhan Ayanbayev –  Some Problems in Vectorial Calculus of Variations in L∞

Penpark Sirimark –  Mathematical Modelling of Liquid Transport in Porous Materials at Low Levels of Saturation

Adam Barker –  Path Properties of Levy Processes

Hasen Mekki Öztürk –  Spectra of Indefinite Linear Operator Pencils

Carlo Cafaro –  Information gain that convective-scale models bring to probabilistic weather forecasts

Nicola Thorn –  The boundedness and spectral properties of multiplicative Toeplitz operators

James Jackaman  – Finite element methods as geometric structure preserving algorithms

Changqiong Wang - Applications of Monte Carlo Methods in Studying Polymer Dynamics

Jack Kirk - The molecular dynamics and rheology of polymer melts near the flat surface

Hussien Ali Hussien Abugirda - Linear and Nonlinear Non-Divergence Elliptic Systems of Partial Differential Equations

Andrew Gibbs - Numerical methods for high frequency scattering by multiple obstacles (PDF-2.63MB)

Mohammad Al Azah - Fast Evaluation of Special Functions by the Modified Trapezium Rule (PDF-913KB)

Katarzyna (Kasia) Kozlowska - Riemann-Hilbert Problems and their applications in mathematical physics (PDF-1.16MB)

Anna Watkins - A Moving Mesh Finite Element Method and its Application to Population Dynamics (PDF-2.46MB)

Niall Arthurs - An Investigation of Conservative Moving-Mesh Methods for Conservation Laws (PDF-1.1MB)

Samuel Groth - Numerical and asymptotic methods for scattering by penetrable obstacles (PDF-6.29MB)

Katherine E. Howes - Accounting for Model Error in Four-Dimensional Variational Data Assimilation (PDF-2.69MB)

Jian Zhu - Multiscale Computer Simulation Studies of Entangled Branched Polymers (PDF-1.69MB)

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Thesis: Definition and Examples in Composition

Glossary of Grammatical and Rhetorical Terms

• An Introduction to Punctuation
• Ph.D., Rhetoric and English, University of Georgia
• M.A., Modern English and American Literature, University of Leicester
• B.A., English, State University of New York

A thesis ( THEE-ses ) is the main (or controlling) idea of an essay , report , speech , or research paper , sometimes written as a single declarative sentence known as a thesis statement . A thesis may be implied rather than stated directly. Plural: theses . It's also known as a thesis statement, thesis sentence, controlling idea.

In the classical rhetorical exercises known as the  progymnasmata , the  thesis is an exercise that requires a student to argue a case for one side or the other.

Etymology From the Greek, "to put"

Examples and Observations (Definition #1)

• "My thesis is simple: in the next century mankind must harness the nuclear genie if our energy needs are to be met and our security preserved." (John B. Ritch, "Nuclear Green," Prospect Magazine , March 1999)
• "We watch baseball: it's what we have always imagined life should be like. We play softball. It's sloppy--the way life really is." (from the introduction to Watching Baseball, Playing Softball)
• "Through Mansfield's skillful handling of point of view, characterization, and plot development, Miss Brill comes across as a convincing character who evokes our sympathy." (thesis statement in Miss Brill's Fragile Fantasy )
• "Suppose there were no critics to tell us how to react to a picture, a play, or a new composition of music. Suppose we wandered innocent as the dawn into an art exhibition of unsigned paintings. By what standards, by what values would we decide whether they were good or bad, talented or untalented, success or failures? How can we ever know that what we think is right?" (Marya Mannes, "How Do You Know It's Good?")
• "I think people are disturbed by the discovery that no longer is a small town autonomous--it is a creature of the state and of the Federal Government. We have accepted money for our schools, our libraries, our hospitals, our winter roads. Now we face the inevitable consequence: the benefactor wants to call the turns." (E.B. White, "Letter from the East")
• "It is possible to stop most drug addiction in the United States within a very short time. Simply make all drugs available and sell them at cost." (Gore Vidal, "Drugs")
• The Two Parts of an Effective Thesis "An effective thesis is generally composed of two parts: a topic and the writer's attitude or opinion about or reaction to that topic." (William J. Kelly, Strategy and Structure . Allyn and Bacon, 1996)
• Drafting and Revising a Thesis "It's a good idea to formulate a thesis early in the writing process , perhaps by jotting it on scratch paper, by putting it at the head of a rough outline , or by attempting to write an introductory paragraph that includes the thesis. Your tentative thesis will probably be less graceful than the thesis you include in the final version of your essay. Here, for example, is one student's early effort: Although they both play percussion instruments, drummers and percussionists are very different. The thesis that appeared in the final draft of the student's paper was more polished: Two types of musicians play percussion instruments--drummers and percussionists--and they are as different as Quiet Riot and the New York Philharmonic. Don't worry too soon about the exact wording of your thesis, however, because your main point may change as you refine your ideas." (Diana Hacker, The Bedford Handbook , 6th ed. Bedford/St. Martin's, 2002)
• A Good Thesis - "A good thesis tells the audience exactly what you want them to know, understand, and remember when your speech is done. Write it as a simple, declarative sentence (or two) that restates the speech purpose and states the main points that support the purpose. Although you may formulate a thesis statement early in the speech development process, you may revise and reword it as you research your topic.' (Sherwyn P. Morreale, Brian H. Spitzberg, and J. Kevin Barge, Human Communication: Motivation, Knowledge, and Skills , 2nd ed. Thomson Higher Education, 2007) - "An effective thesis statement singles out some aspect of a subject for attention and clearly defines your approach to it." (David Blakesley and Jeffrey L. Hoogeveen, Writing: A Manual for the Digital Age . Wadsworth, 2011)

Examples and Observations (Definition #2)

" Thesis . This advanced exercise [one of the progymnasmata] asks the student to write an answer to a 'general question' ( quaestio infina )--that is, a question not involving individuals. . . . Quintilian . . . notes that a general question can be made into a persuasive subject if names are added (II.4.25). That is, a Thesis would pose a general question such as 'Should a man marry?' or 'Should one fortify a city?' (A Special Question on the other hand would be 'Should Marcus marry Livia?' or 'Should Athens spend money to build a defensive wall?')" (James J. Murphy, A Short History of Writing Instruction: From Ancient Greece to Modern America , 2nd ed. Lawrence Erlbaum, 2001)

• Proof in Rhetoric
• Definition and Examples of Progymnasmata in Rhetoric
• Definition and Examples of Body Paragraphs in Composition
• Unity in Composition
• Supporting Detail in Composition and Speech
• Definition and Examples of Analysis in Composition
• Understanding General-to-Specific Order in Composition
• Current-Traditional Rhetoric
• Outlines for Every Type of Writing Composition
• Composition Type: Problem-Solution Essays
• Definition and Examples of Formal Essays
• Understanding Organization in Composition and Speech
• Arrangement in Composition and Rhetoric
• Definition and Examples of Composition-Rhetoric
• How to Write an Abstract

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[ thee -sis ]

He vigorously defended his thesis on the causes of war.

Synonyms: proposal , contention , theory

• a subject for a composition or essay.
• a dissertation on a particular subject in which one has done original research, as one presented by a candidate for a diploma or degree.
• Music. the downward stroke in conducting; downbeat. Compare arsis ( def 1 ) .
• a part of a metrical foot that does not bear the ictus or stress.
• (less commonly) the part of a metrical foot that bears the ictus. Compare arsis ( def 2 ) .
• Philosophy. Hegelian dialectic

/ ˈθiːsɪs /

• a dissertation resulting from original research, esp when submitted by a candidate for a degree or diploma
• a doctrine maintained or promoted in argument
• a subject for a discussion or essay
• an unproved statement, esp one put forward as a premise in an argument
• music the downbeat of a bar, as indicated in conducting
• (in classical prosody) the syllable or part of a metrical foot not receiving the ictus Compare arsis
• philosophy the first stage in the Hegelian dialectic, that is challenged by the antithesis
• The central idea in a piece of writing, sometimes contained in a topic sentence .

Word History and Origins

Origin of thesis 1

Example Sentences

“The Saudis have been proving the thesis of the film — they do in fact have an army,” said Thor Halvorssen, founder and chief executive of the nonprofit Human Rights Foundation, which funded the movie.

It’s a hypothesis that Bush pursued in her master’s thesis, and last year she began attending virtual Goth parties in a final round of field work before defending her doctoral thesis later this year.

While this partnership was planned prior to the coronavirus outbreak, co-founder Jordana Kier said the pandemic instantly proved out the expansion thesis.

They’ve had to defend that thesis for a very, very long time in front of a variety of different customers and different people.

Over the past decade, In-Q-Tel has been one of the most active investors in the commercial space sector, with a broad investment thesis that touches many aspects of the sector.

In “Back Home,” Gil also revisits the nostalgia for the South explored in his Johns Hopkins thesis, “Circle of Stone.”

At least father and son were in alignment on this central thesis: acting “gay”—bad; being thought of as gay—bad.

Her doctoral thesis, says Ramin Takloo at the University of Illinois, was simply outstanding.

Marshall McLuhan long ago argued the now accepted thesis that different mediums have different influences on thinking.

He wrote his Master's thesis on the underrepresentation of young people in Congress.

And indeed for most young men a college thesis is but an exercise for sharpening the wits, rarely dangerous in its later effects.

It will be for the reader to determine whether the main thesis of the book has gained or lost by the new evidence.

But the word thesis, when applied to Systems, does not mean the 'position' of single notes, but of groups of notes.

This conclusion, it need hardly be said, is in entire agreement with the main thesis of the preceding pages.

Sundry outlying Indians, with ammunition to waste, took belly and knee rests and strengthened the thesis to the contrary.

Related Words

• proposition
• supposition

What Is The Plural Of Thesis?

Plural word for  thesis.

The plural form of thesis is theses , pronounced [ thee -seez ]. The plurals of several other singular words that end in -is are also formed in this way, including hypothesis / hypotheses , crisis / crises , and axis / axes . A similar change is made when pluralizing appendix as appendices . 

Irregular plurals that are formed like theses derive directly from their original pluralization in Latin and Greek.

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Is copying the exact statement of a definition or a theorem considered plagiarism?

Let's say in a paper when I am talking about a theorem someone else proved, I state the result in the exact same way, word for word, as in their paper. Is this considered plagiarism? I would still give credit and citation to the result, just that I don't paraphrase the statement.

• mathematics

• 10 It is plagiarism only if you state it without reference, implicitly claiming that it is your own discovery. If you say: "The well-known Mean Value Theorem" and then state it, you are OK, even if your statement is word-for-word identical to the version in some book. When stating something not as well known as that, provide a reference (to help the reader, more than to avoid accusations of plagiarism). –  GEdgar Commented May 20, 2021 at 11:41
• 4 Does this answer your question? Is copying equations plagiarism? –  Louic Commented May 20, 2021 at 11:59
• @Louic I think copying an equation is fine, but not paraphrasing seems like I am stealing people's hard work. –  k99731 Commented May 20, 2021 at 15:57
• 2 @k99731 Academically it isn’t, as long as you give them credit. –  RBarryYoung Commented May 20, 2021 at 17:53
• 1 @kosmos in sensible systems, that flag would go a human marker (academic or TA) would would spot the citation and context and not worry. Not all systems are sensible; I've heard recently of students being auto-failed for plagiarism scores on turnitin, and I've also seen scores reach over 20% just from the bibliography and a few short common phrases. –  Chris H Commented May 21, 2021 at 12:10

3 Answers 3

In mathematics, often there are highly optimized/perfected statements of theorems. It would be silly to alter them (introducing damage?!) just for the sake of avoiding exact quoting. Cite, that's all.

That is, unless you have something to add to their idea, there's scant point to changing the wording... apart from the risk of mis-stating them!... just to meet a sort of fake goal. Cite and acknowledge. Be honest. With citation, what could possibly be the objection to quoting a perfected assertion of a good theorem?

• 5 'unless you have something to add to their idea, there's scant point to changing the wording' Unless, for example, you're an undergraduate and one of the learning outcomes you're supposed to demonstrate that you've achieved is something equivalent to "students will be able to review and rewrite key theorems". Learning outcomes or items in marking rubrics that involve the word "understand" often are equivalent to that. –  Daniel Hatton Commented May 20, 2021 at 7:39
• 8 I believe there is one subtle issue. Copying a theorem is not plagiarism, provided that the source is cited. In fact, even copying ten theorems from a single source is not plagiarism, provided that the source is cited. However, from the perspective of the copyright holder (often a corporate entity) the latter may appear as a breach of copyright. Whether something like fair dealing/fair use exists and is applicable (and to what extent) depends on the jurisdictions involved. Thus, if one has an intention to "copy" a significant part of a scientific work, it may be safer to paraphrase. –  user9716869 - supports Ukraine Commented May 20, 2021 at 8:11
• 2 @user9716869, I strongly agree. Copyright must also be considered. It is a separate issue from plagiarism. But also note that there is a rule (usually included in copyright laws) that you can't copyright something that can be said in only one way. Some math falls under this rule. –  Buffy Commented May 20, 2021 at 11:07
• 1 @user9716869 math.meta.stackexchange.com/a/1854/152317 Basically it depends on how much "idea" vs "expression" the theorem is. If it is the mathematical equivalent of simple language then it may not be copyrightable at all...even if the idea is quite complex, because ideas aren't copyrightable. –  user3067860 Commented May 20, 2021 at 14:23
• 2 I'd say "the well-known Mean Value Theorem" doesn't need a citation because (a) it is well known, and (b) calling it well-known tells us that you didn't invent it, even if I personally didn't know it. –  gnasher729 Commented May 21, 2021 at 9:27

The first sentence on the wikipedia article for plagiarism reads:

Plagiarism is the representation of another author's language, thoughts, ideas, or expressions as one's own original work.

If you state a result or definition that someone else came up with, (in your own words or theirs), and say that you came up with it, then that's plagiarism.

If you state a result or definition that someone else came up with, (in your own words or theirs), and properly attribute it to the original author, then that's not plagiarism.

Things are a bit different when talking about "classical" results, if I would have need to state, say, the fundamental theorem of calculus, I would either:

• state the theorem in my own words and give no attribution,
• copy the theorem from e.g. a textbook and give proper attribution.

The point here is that in this case there is no risk of me giving the impression that I'm trying to pass off the result itself as my own. Further, in the case of 1, I am actually using my own words, so there is no risk of plagiarism. In the case of 2, I am using someone else's words, and thus give proper attribution.

It should be noted that plagiarism is distinct from, but related to, copyright infringement. If you directly copy a passage of text (or piece of music, etc.), no amount of correct attribution can absolve you of copyright infringement. However, this does not mean that you can never copy text directly. Doing so might be considered fair use, or you could have permission from the copyright holder, or the work might be exempt from copyright in the first place.

In general, you should make sure that you commit neither plagiarism, nor copyright infringement. (In the above example, I would feel confident that copying a single theorem from a textbook, and using it in a longer work would not be copyright infringement, but I am not a lawyer, and this is not legal advice.)

• 2 +1 For explaining what plagiarism is. Plagiarism isn't about exact wording, so paraphrasing is irrelevant. –  jamesdlin Commented May 21, 2021 at 0:56

It is not plagiarism if it is cited and credited correctly.

What would make it plagiarism is obscuring or hiding the citation or referring to the work of others in a misleading manner.

You must log in to answer this question.

Not the answer you're looking for browse other questions tagged mathematics plagiarism ..

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Thesis Abstracts

First steps towards characterizing the completions of catenary domains.

Andrew Aramini

Let T be a complete local ring of dimension at least 3. For any finite set of nonmaximal, nonassociated prime ideals of T, there exists a local domain S such that the completion of S (with respect to its maximal ideal) is T, and each prime ideal in the chosen set has the same intersection with S. Furthermore, this intersection is equal to the principal ideal yS for some nonunit, nonzerodivisor y in T. In addition, there exists a countable subset of the prime ideals of T such that each such prime ideal’s intersection with S is also equal to yS.  

Bayesian Hierarchical Model for Estimating Particulate Matter (PM10) Levels in South Korea

Youngsoo Baek

High levels of particulate matter (PM) have raised health concerns in the East Asian region, including South Korea, China, and Japan. The volatile nature of particle transport, and the complexity of dependencies across multiple meteorological factors across space and time, pose various challenges to modeling PM levels and making accurate forecasts. We propose a Bayesian hierarchical regression model for Gaussian process of PM log-levels. The model extends the Multivariate Spatiotemporal Mixed Model (MSTM) framework proposed by Bradley, Holan, and Wikle (2015), through choosing the basis functions applicable to point-referenced dataset. Our major innovation is the extension of Moran’s I basis functions to point-referenced dataset, systematically accounting for historical changes in the spatial coordinates of the stations in the data. We fit the model to a dataset of particulate matter with diameter less than 10 μg/m3 (PM10) collected in South Korea, publicly available from the Korean Meteorological Association (KMA). Due to the computationally taxing nature of Markov Chain Monte Carlo methods, we fit models to three subsamples of the data. Our results show that the model is computationally efficient, produces reliable forecasts of PM levels up to a short lag of 6 to 12 hours ahead, and handles missing values with ease. We benchmark the predictive performance of our model against a similar hierarchical model based on empirical orthogonal functions (EOF), which requires imputation of response data. This thesis marks the first attempt to introduce a systematic Bayesian approach to estimating and forecasting PM level data in South Korean region. 

Modeling Resource Cooperation in Invasive Species Bridgehead Systems

Thomas Benz

Bridgehead effects are a recently-discovered invasive species dispersal pattern, whereby invasive populations act as the source for further invasions. We construct a discrete-time stochastic model of bridgehead invasion systems. Furthermore, we analyze how “resource cooperation” between distinct geographic areas could be effective in reducing the spread of invasive alien species.

Protein Structure and Knot Theory

Judah Devadoss

A protein’s structure defines its function, and like knots, they can be though of as the embedding of a strand in three dimensions projected into a two-dimensional diagram. This thesis looks to classify proteins using multiple different methods, choosing specific structures that will account for the limitations that proteins offer. We will first look at the basic rules of equality we define for two diagrams. We will then look at representing proteins using Gauss codes, or a strings of numbers and letters, and how we can equate these codes with changes allowed in diagrams. Finally, we will look at how we can apply an algebraic group structure to proteins using quandles.

Span of the Bracket Polynomial and Triple Crossing Projections of Knots and Links

Jonah Greenberg

In this paper, we construct a large class of knots for which span [K] = 8c3(K) and then extend ideas about alternating and adequate knots to triple-crossing projections by using the class of knots for which span [K] =8c3(K) as the analog for alternating in the triple-crossing case.

Expanding Zero-Forcing to Multi-Color Forcing on Graphs

Let G = (V, E) be a finite connected graph with all vertices colored blue or white, where V is the vertex set and E is the edge set. The vertices in set V can either be a vertex colored blue or a vertex colored white of G. Now consider the following rule/condition: if u,v V and u, a blue vertex, has only one white neighbor, v, then u forces v to become blue. This process is repeated for all vertices in V until it cannot occur anymore. This process is known as zero-forcing. In this thesis, we propose a theory that expands the idea of color forcing called multi-color forcing. We propose a color forcing step and show that under all possible coloring rules all graphs results in a unique termination state. Moreover, we study the theory that arises from choosing this color forcing step. We end the thesis by giving some future areas of study.

Topology of Random Simplicial Complexes

Simplicial complexes are used in topological data analysis (TDA) to extract topological features of the data. In this thesis, we are interested in understanding the topological invariants of simplicial complexes of data generated from a stochastic process. We study the expected values of Euler characteristics and Betti numbers of random simplicial complexes from the perspective of TDA. We survey the theory of TDA and random geometric graph theory. We prove asymptotic formulas of the expected Euler characteristics of random Vietoris-Rips complexes. By incorporating theoretical results of random simplicial complexes and symbolic regression, we propose a computational approach to understand the Betti numbers and find models for the expected values 0 and 1 of random Vietoris-Rips complexes.

Tropical Varieties of Cryptography

Jian Hong Lu

In the current state of cryptography, one our most secure cryptographic systems is derived from incredibly simple curves defined by equations of the form y2 = x3 + Ax + B, also known as elliptic curves. Our thesis further explores the possibilities of cryptography within the system of tropical mathematics. Mainly we rewrite all operations of classical mathematics with the operations based on our max-plus semi-ring (R {- ∞}, , ), where x y = max{x,y} and x y = x + y. Part 1 of this thesis will present some basic definitions, and properties of tropical geometry so that our readers will get a flavor for the mathematics which we are exploring. In addition, we will present some definitions and examples regarding metric graphs which will later be used to prove the main theorem. We will also introduce tropical linear algebra and how this could be used to define a cryptographic system similar to classic Diffie-Hellman cryptographic systems. Part 2 will introduce classic elliptic curve cryptography, and present a proof by Vigeland that defines a group law on tropical elliptic curves. We will also present a new different proof of the doubling map on tropical elliptic curves in R2. This section will also go into detail about how we construct a Diffie-Hellman key exchange algorithm based on the tropical elliptic curve. Part 3 presents and studies a new group law on tropical elliptic curves in R3.

Bayesian Estimation of Age at First Capture in Mark-Recaputure Studies of Trinidadian Guppies

Sophie Diane Lu

The age of an organism is a strong predictor of organismal fitness. However, in ecological studies, age cannot be measured directly for many wild populations. Furthermore, age correlates reasonably well with other organismal traits that researchers can directly measure. The estimation of these traits over successive time periods allows the estimation of age via these other variables. 

The Guppy Project has been conducting a longitudinal study on populations of Trinidadian guppies, the model organism system used to study ecological and evolutionary processes for over a decade. In order to understand population attributes such as aging and growth in the wild, it is important to be able to identify the age of an organism. Since the guppies are small and born live, they cannot be marked until they reach a specific length. Thus, the age of these organisms are unknown at recapture during the monthly mark-recapture procedures. 

We constructed a hierarchical model using a Bayesian framework to estimate the age of a given fish in a population. Using early-life data and mark-recapture census data from two series of data over consecutive three-months each, we generated inferences for the birth dates for each fish, which gives the estimates for age for each fish. By this model structure, we may input the sizes of guppies, measured by standard length, and extract reliable age estimates. Our hierarchical model structure uses latent categorical indicators to model the imperfect identification of specific individuals in size cohorts in the mark-recapture study, until the individuals are large enough to receive uniquely identifiable marks. This approach is novel to methodology in mark-recapture studies. 

Here be Legendre Dragons: An Analysis of Paper Folding Diagrams Corresponding to Values of the Legendre Symbol

Grace McCormick Mabie

We examine patterns and symmetries of the Legendre Symbol with the help of paper folding diagrams. These diagrams, which we call Legendre Dragons, reveal properties of the Legendre Symbol through attributes which we have named area, slope, and diameter. We conjecture strict upper and lower bounds on the diameter of Legendre Dragons, which would reveal a new perspective on the randomness of the values of the Legendre Symbol for a given prime p.

Uncountable Noetherian Rings With Unusual Prime Ideal Structures

Anya Michaelsen

In this paper we construct two rings. The first is an uncountable n-dimensional excellent regular local ring with a countable spectrum. The second, is an uncountable 2-dimensional ring with two maximal ideals, N and M, where N contains only countably many prime ideals, all of which are finitely generated, and M contains uncountably many prime ideals. When localized at N, this yields an uncountable 2-dimensional Noetherian ring with a countable spectrum.

A Novel Method of Stability-Based Cluster Validity for Density-Based and Spatiotemporal Clustering

Eric Rosenthal

We introduce a novel stability-based measure of cluster validity designed specifically for density-based clustering and spatiotemporal clustering. We demonstrate the properties of this measure on simulated data as well as the Iris dataset for standard DBSCAN, and demonstrate the effectiveness of the measure at finding optimal clusterings. We then adapt our measure to work on spatiotemporal datasets and demonstrate its effectiveness by examining its performance on simulated spatiotemporal data. We apply our validity measure to two real-world spatiotemporal datasets, one consisting of weather data from Europe, the other consisting of voter registration data from California.

Kostant’s Partition Function and Multiplex Juggling Sequences

Anthony Lamont Simpson

In this thesis, we show the combinatorial equivalence of two combinatorial problems. The first is partitioning the weights of classical Lie algebras using the positive roots of the Lie algebra. The second problem is counting multiplex juggling sequences with certain properties. We first solve a problem previously posed by Harris, Insko, and Omar, then show the general combinatorial equivalence of these problems. Our work focuses primarily on partitioning in a Lie algebra of type A, but we relate the results to partitions of weights of Lie algebras of other types and show some equivalences between two extensions of multiplex juggling sequences.

On Some Symbolic Dynamical Systems or Rank-One and Two

This thesis is divided into two parts. The first part is an exposition on Cellular automata. Specifically, we look at two different definitions of cellular automata and use properties of cellular automata to prove Hedlund’s theorem which directly shows the equivalence of the definitions.

In the second part, we study symbolic rank-one transformations in detail. We provide an intuition in Section 2.5 on how the symbolic sub-shift space is related to measure preserving systems in measure theory. Using symbolic sub-shifts,we can reduce the abstruse theorems and problems in measure theory into puzzles with binary numbers that are much easier to understand. In addition to an exposition on existing theorems in rank-one systems, we first prove Theorem 2.2.5 which shows that the definitions of rank-one words in [4] and [5] are equivalent. We then use a symbolic argument to prove Theorem 2.4.11 which shows that the Thue-Morse sequence is not a rank-one sequence, before providing definitions of rank-n words and rank-n systems in the symbolic sub-shift space in Section 2.8. Theorem 2.8.6 classifies the conditions which different infinite words can have the same symbolic shift system. Finally, Theorem 2.9.8 shows that the system associated with the Thue-Morse sequence is not rank-one.

A Numerical Investigation of the Traveling Wave in the Replicator-Diffusion Equation

The replicator equation fails to capture the population dynamics in which individuals are distributed throughout a space. One solution to this shortcoming is to incorporate a diffusion term, thereby providing a spatial structure and allowing individuals to move. We call the resulting equation the replicator-diffusion equation. In this thesis, we study these evolutionary game dynamics with a spatial component through two different reaction – diffusion systems, both in 1D and 2D, based on previous works by Hutson, Vickers, and Cressman via computational simulation. We numerically investigate the behavior of the traveling wave in both dimensions and give criteria for the direction of the traveling wave in 2D. We also explore other nuances in the 2D case, namely turning points and wave shapes.

On Higher Distance Commuting Matrices

Madeleine Constantina Elyze

In general, matrix multiplication is not commutative. However, sometimes pairs of matrices do commute. We say that two matrices A and B commute, denoted A<–>B, if AB-BA=0. The collection of pairs of non-scalar matrices that commute forms an algebraic affine variety in C 2n2 , where C denotes the complex numbers. In the case that A and B do not commute, A <-/-> B, it is still possible that A and B commute with some common, non-scalar matrix X. Then we say A<–>X<–>B. In this way, we can construct chains of matrices of arbitrary lengths, A<–>X_1<–>…<–>X_k<–>B. We say that A is distance k+1 away from B if our chain is the shortest such path between A and B. This thesis is concerned with understanding the algebraic properties of these chains in C 2n2 space. We show that the collection of distance less than or equal to 2 matrices forms an algebraic variety and offer intuition for proving that the collection of distance less than or equal to 3 matrices also forms a variety.  

The Zeckendorf Game

Alyssa Epstein

A brilliant theorem of Zeckendorf proves that every positive integer $n$ can be written as the sum of unique, non-adjacent Fibonacci numbers. This theorem generalizes: Miller and Wang showed that every positive linear recurrence relation defines a unique legal decomposition, where legal means the recurrence relation cannot be applied again and the summands are appropriately bounded. This thesis examines the Zeckendorf game, a two player game on a specific recurrence relation. This game is defined on the Fibonacci numbers and can be meaningfully extended to all positive linear recurrence relations of the form F n = {i=1}^{k} cF_ n-i . We prove that the game always terminates at the appropriate (generalized) Zeckendorf decomposition, but that there are always games of multiple lengths. We also find upper and lower bounds on the number of moves taken in a game. For the Fibonacci Zeckendorf game, we show upper bounds on the order of nlog ( n ); for all other Zeckendorf games, we show an upper bound on moves that grows linearly with n. The thesis centrally contains an analysis of winning strategies, including a proof of the main theorem: for the Fibonacci Zeckendorf game, Player 2 has the winning strategy for all n > 2.

Almost Excellent Unique Factorization Domains

Sarah M. Fleming

Let ( T ,m) be an equidimensional complete local (Noetherian) ring such that no integer of T is a zero divisor in T > 1.  In addition, suppose T contains the rationals, | T |=| T /m|, and the set of all principal height one prime ideals of T has the same cardinality as T .  We construct a universally catenary unique factorization domain A such that \widehat{A}= T and such that uncountably many height one prime ideals of T have nonzero intersection with A and have geometrically regular formal fibers.  If T is assumed to be normal, then we can ensure that the generic formal fiber is also geometrically regular.  Furthermore, in the case where T is a normal domain, we can make A “close” to excellent in the following sense: we can show that the formal fibers at the prime ideals of height not equal to one are geometrically regular.

Combinatorial Problems Related to Peaks, Pinnacles, Descents, and Derangements

Isabella Huang

We say a permutation π = π 1 π 2 … π n Î n has a peak at index i if π i-1 < π i > π i+1 , has a pinnacle at value π i if π i-1 < π i > \ π i+1 , has a descent at index i if  π i > π i+1 , and is a derangement if for all i Î [n], π i \neq i . In this thesis, we provide formulas for the number of derangements with no peaks, one descent, and special cases of two descents, the last of which connects this work to counting diagonal staircase paths. In 2017, the work of Davis, Nelson, Petersen, and Tenner studied pinnacles of a permutation and asked whether there was a particular group action that preserves pinnacles. We consider the proposed group action introduced by Foata and Strehl and find that while it does preserve pinnacles of a permutation, the orbits do not encompass all elements having the same set of pinnacles. Thereby, we establish and measure the insufficiency of this particular group action. We end the thesis with future directions of research in combinatorial problems related to peaks, pinnacles, descents, and derangements with a focus on permutahedra.

Combinatorial Conditions for Nonsingular Rank-One Transformations

Sumun Sitalakshmi Iyer

A transformation T of a measure space (X, B, m) is measure-preserving if for any set C in B, we have that m(T^{-1}(C)=m(C).  We say that T is nonsingular if for any set C in B we have that m(T^{-1}(C))=0 if and only if m(C)=0.We provide necessary combinatorial conditions for a transformation to be nonsingular rank-one. We also develop a class of nonsingular Morse sequences that we conjecture to have rank two.

Network Topology, Pollen Movement and Models of Insect Behavior in Neighboring Flower Communities

Molly Riley Knoedler

The dynamics and structure of networks of ecological interaction offer insight into stability, resilience, co-evolution, and diversification of ecosystems. Visitation networks, which represent the interaction of plants and their potential pollinators, are of particular interest due to the world-wide decline of insect populations and the importance of pollination to agriculture. In Chapter 1, I examine topological properties and pairwise visitor partitioning at two sites on a small island to better understand fine-scale variation between neighboring flower communities. These results are evidence of the possibility of multiple structures of stable organization in similar natural ecosystems. In Chapter 2, I discuss the results of an agent-based model I developed that investigates how the rules of insect behavior in a heterogeneous floral landscape dictate to pollen movement. I find that even with significantly different visitor partitioning between conspecific flowers, pollen can move over large areas and keep neighboring flower communities genetically connected. While agent-based modeling of pollen movement is not yet widely used, this tool has great potential to improve understanding of pollination in agricultural contexts and aid efforts to protect declining insect populations.

Pedagogical Approaches to Mathematics Instruction: Finding a Balance Between Lectures and Discovery

Edward Lachance Lauber

Math education is an issue of critical importance in the United States and around the world, yet there is still no scientific consensus on the best ways to teach math. One of the central debates concerns the use of discovery-based learning in comparison to more standard lecture techniques. Some theorists argue that students cannot learn without discovering material for themselves, while others contend that more structured lectures enable students to learn much more. In this study, we set up multiple classrooms with three different teaching paradigms: a lecture condition, a discovery condition, and a mixed condition. Over the course of three days, participants studied the same material on cake-cutting and fair division. Our findings revealed no significant differences between conditions, indicating that perhaps there is no single best way to teach this material.

Assessing Critical Mass at UC-Berkeley: Creating Predictive Models for Affirmative Action Policies in Undergraduate Admissions in the United States

Daniel Paul Maes

Affirmative action refers to hiring and recruiting practices designed to combat discrimination against members of certain demographic groups. These policies are used in settings ranging from federal contractors to local employment to public education, and can focus on race, ethnicity, or gender. Due to the broad applicability and direct social impact of affirmative action, substantial effort has gone into monitoring the necessity and effectiveness of these policies. This effort has manifested itself in frequent legal and state action over the past forty years. In this thesis, we focus on the application of race-based affirmative action policies in public undergraduate college admissions in the United States, specifically through a case study of admissions to the University of California, Berkeley. We make three primary contributions. First, we introduce a quantitative framework through which to interpret a key concept used in contemporary affirmative action litigation: “critical mass.” Historically, policies have been assessed using retroactive data studies. However, using predictive models would reduce the monetary and temporal costliness of such studies. Thus, second, we construct a predictive model of college admissions demographics using Markov Chains. Third, we bring together the two previous contributions, using our quantified version of the critical mass criterion as a benchmark for assessing the outcomes of the predictive model. The type of mathematical model we construct can be modified for use at other universities or for affirmative action applied to other axes, including gender.

Finding a Model for the ensity of States of RNA

Eliza Woolworth Matt

RNA molecules can adopt a multitude of fold configurations of varying free energy G. The Boltzmann probability suggests the average energy should be near the minimum free energy, but surprisingly we find the difference between the average energy and minimum free energy to be much larger than the product of the Boltzmann constant and the temperature. In this thesis, we show this is because the density of high-energy states grows more quickly than the Boltzmann factor suppresses. We observe this for RNAs across sequence lengths and types, both randomly generated and natural, coding and non-coding. We find that both a flattened exponential and a hyperbolic function are able to approximate well the observed density of states better than either a power law function or a standard exponential function.

Longitudinal Regression Trees and Their Application to Body Mass Index Growth Trajectories

Anna Neufeld

A growing body of scientific literature suggests that exposure to environmental pollutants during key periods of development can cause lasting changes in an individual’s metabolism. These changes can impact an individual’s body mass index (BMI) trajectory and risk of obesity later in life. Given the complex ways in which environmental pollutants interact with one another and the challenges of studying trajectories over time, nontraditional statistical models are needed to truly understand the relationship between environmental pollutants and an individual’s BMI trajectory. Our goal is to cluster individuals with similar BMI trajectories and similar chemical exposures so as to understand which environmental pollutants may cause heightened risk of obesity. We propose longitudinal regression trees as a promising approach to accomplishing this goal. While a few algorithms for longitudinal regression trees have been previously developed, they have never been applied with the goal of clustering growth trajectories. We compare several existing longitudinal regression tree algorithms in a simulation study setting, and evaluate the potential of these algorithms for tackling the BMI growth trajectory problem. Along the way, we propose modifications to existing algorithm so that we can group individuals by the change in their BMI over time, rather than by the level of their BMI. We then demonstrate the potential of the existing algorithms and the modified algorithm on real BMI trajectories from the National Longitudinal Survey of Youth (NLSY).

Multi-Crossing Braids

Daishiro Nishida

Traditionally, knot theorists have considered projections of knots where there are two strands meeting at every crossing. A multi-crossing is a crossing where more than two strands meet at a single point, such that each strand bisects the crossing. In this thesis we generalize ideas in traditional braid theory to multi-crossing braids. Our main result is an extension of Alexander’s Theorem. We prove that every link can be put into an n-crossing braid form for any even n, and that every link with two or more components can be put into an n-crossing braid form for any n. We find bounds on the number of strings or crossings necessary to represent a link in an n-crossing braid. We explore different ways to obtain multi-crossing braids, and use these techniques to find new multi-crossing numbers.

Finite Subsets of the Prime Spectra of Local UFDs

Alex Paul Semendinger

In a 2017 paper, Avery et al. characterized the completions of noncatenary local (Noetherian) UFDs. This was accomplished using a construction similar to one used by Heitmann in a 1993 paper. However, we know very little about the prime ideal structures of the UFDs obtained with this construction. We adjust Avery et al.’s techniques, allowing for greater control over the prime ideal structure of the constructed UFDs. This expands our collection of examples of noncatenary local (Noetherian) UFDs and gives insight into the question of which partially ordered sets can arise as the prime spectrum of a Noetherian UFD.

Using Data to Predict Hospital Readmissions at Berkshire Medical Center

Hallee Erica Wong

Hospital readmission — whether a patient returns to the hospital within 30 days of discharge — is a popular metric in healthcare policy because frequent hospitalizations are a negative outcome for both hospitals and patients’ health. A model to identify patients with high risk of readmission would enable hospitals to optimize the allocation of resources. Analyzing a dataset of hospitalizations from Berkshire Medical Center, we fit models to predict readmission using logistic regression, decision trees, ensembles of models, and integer programming-based methods. To strategically utilize high dimensional medical code data, we consider ensemble models in which patients are stratified by primary diagnosis and separate models are fit for each group. We show that an ensemble model stratified on the existing hierarchy in the International Classification of Diseases (ICD-10) performs significantly worse than a single global model. We propose a new method, Categorical Co-Frequency Analysis (CCoFA), that uses random forests to identify relationships between categorical labels. Applying CCoFA to identify three disparate clusters of patients defined by diagnosis, we show the performance of an ensemble model stratified on CCoFA clusters is not statistically significantly different from that of a single global model. Additionally, we compare the performance of RiskSLIM (Ustun and Rudin, 2017), an integer programming-based method, to logistic regression and decision trees. Using RiskSLIM to generate a risk scoring system with integer coefficients leads to a model with lower accuracy than logistic regression with real-valued coefficients.

An Uncountable Dimension-Two Ring With a Countable Spectrum

In this paper, we construct a quasi-semi-local ring with two maximal ideals M and N, where M contains only countably many prime ideals but N contains uncountably many. When we localize this ring at its maximal ideal M, we produce an uncountable dimension-two Noetherian local ring with a countable spectrum, reproducing a result of Colbert for dimension-two rings.

Periodic Paths on the Triangle and Hexagon Billiard Tables

Megumi Asada

Imagine a frictionless, air resistance-less fantasy world with completely elastic collisions. For some reason, you decide to play billiards in this world except your billiard ball contains an infinite supply of paint that it releases as it travels. You also decide to play on equilateral triangle and hexagon billiard tables, because why not? Interestingly, you notice that depending on the angle with which you release the ball, the path drawn in paint on the billiard table starts to repeat itself, fixing the path drawn in paint after some period of time. I’m interested in these types of paths, which we call periodic. Specifically, given a direction vector that you know is periodic, what is the period? How many times will the billiard ball hit the walls of the table before repeating its trajectory? We’ll resolve this case for the triangle billiard table and explore progress towards understanding the hexagon billiard table.

Properties of Finite Systems of Fixed-Length Cranks

Paul Pierre Baird-Smith

I consider the paths of circular cranks that rotate at fixed speeds in a plane. For a single crank, this is simple: move in a circle; but when one crank is attached to another, a whole new family of curves appears. This talk will focus on surprising properties of these systems in R 2 , including commutativity and minimality of systems and their curves. Notably, we show that we can draw any polynomial on any bounded interval with these systems.

Probabilistic Bounds On Binary Classification with Dependent Experts

Weighted expert voting is central to the areas of decision theory and statistical learning. In the classical Naive Bayes’ framework, it is assumed each expert votes independently. We investigate a model of expert voting in which votes are no longer assumed to be independent. We give an optimal decision rule for this model in the case when the dependencies between experts, as well as expert competences are known. We give error estimates for this decision rule. We also investigate the case in which the dependencies between experts are unknown. Under the model assumptions, we show the asymptotic correctness of the spectral clustering algorithm with certain weights as the number of samples tends to infinity. Additionally, we give explicit lower bounds in a small case for the probability spectral clustering succeeds.

Simultaneous Variable and Factor Selections Via Sparse Group Lasso in Factor Analysis

Yuanchu Dang

This thesis investigates applications of penalization techniques to factor analysis models. In a factor analysis model one assumes that there is a linear relationship between the manifest variables (i.e. observable variables) and the hidden factors of interest. Depending on the structure of the factor loading matrix, it can be further classified as either an Exploratory Factor Analysis (EFA) model or a Confirmatory Factor Analysis (CFA) model. Previous research (Hirose and Konishi, 2012) applies the Group Lasso method, a penalization technique with group-wise sparsity, to EFA in determining the number of observable variables. In this thesis we consider adapting the Sparse Group Lasso penalty to a factor analysis model, which is a more flexible approach that allows both group-wise and parameter-wise sparsity of the factor loadings. With the help of the Sparse Group Lasso technique, one can achieve selecting both the number of observable variables and the number of factors for each observable variable. Therefore, it can be used in CFA models. We show that the proposed method can better identify the true underlying structure of a factor analysis model. Moreover, our simulation studies show that the new method gives more accurate estimation of the model parameters than the existing method.

Benford’s Law Beyond Independence: Copulas and Detecting Fraud

Rebecca Durst

Benford’s law describes a common phenomenon among many naturally occurring data sets and many common distributions, such as the exponential distribution, in which the leading digits of the data points are distributed according to log_{B}[(d+1)/d].  It is so common, in fact, that it is often applied in practice to detect fraud in fields related to science, finance, and even politics. Thus, significant effort has been made to understand when and how distributions will display Benford behavior.  Most of the previous work on Benford’s law, however, has been restricted to cases of independent variables, and very little is known about its potential application in situations involving dependence.  In this paper, we employ the theory of Copula distributions to investigate the Benford behavior of a product of two random variables that may be dependent. Using this copula theory, we provide a method for quantifying and numerically approximating the Benford behavior of a product of two random variables whose joint distribution function is modeled by the copula C.  We then develop a concept of distance from a Benford distribution for products in which one or more of the marginals is a Benford distribution and provide an upper bound for this distance that depends only on the copula C.  We then conclude our investigations with a consideration of a concept of goodness of fit for the Benford behavior of a data set that is being fit to a particular copula model.

A New Connection Between the P ólya-Vinogradov and Burgess Inequalities

Elijah Fromm

The Pólya-Vinogradov inequality bounds sums over Dirichlet characters without taking the length of the sum into account. For a character c with modulus q , this bound becomes trivial when the sum is shorter than a constant multiple of  log q . Burgess’ bound, which takes the length of the sum into account, remains nontrivial as long as the sum is longer than some constant multiple of q  + Î. Vinogradov conjectured that character sums of length longer than q Î exhibit cancellation, for any Î > 0. Here, we show that a modest improvement of the Pólya-Vinogradov bound for primitive even quadratic characters would give nontrivial bounds implying Vinogradov’s conjecture on all primitive odd quadratic characters with prime modulus. We also show that whenever the mean of a completely multiplicative function f : N ® [-1,1] is large, the logarithmic mean of f must also be large.

A Comparison of Bayesian and Frequentist Model Averaging in Predicting the Demographics of Voter Turnout

Kathryn Grice

Better performing than its constituent models, a model average can preempt the dangers of choosing a single model when model specification is uncertain. Model averaging can take place under either the frequentist or Bayesian paradigm, although the underlying assumptions and methodology are vastly different. Here, we evaluate the performance of these approaches to model averaging in the context of voter turnout in US general elections. Using county-level demographic data to predict the turnout of various demographic groups in six states, frequentist and Bayesian model averages see differing levels of success, indicating that a comparison of these approaches is more complex. Further, this study seeks to debunk myths of homogeneity in the voting habits of these demographic groups: indeed, groups that show highly varied trends in turnout between states, in particular those defined by race, are more difficult to predict using model averaging. In the context of a broadening role of statistical analysis before, during, and after elections, both approaches to model averaging offer strengths for demographic analysis and bespeak the inadequacy of generalizations based on demographic group alone.

Investigating Central-Point Vanishing of Families of L-Functions Using the 2-Level Density

Anand Hemmady

In the 1970s, Dyson and Montgomery discovered an unexpected connection between the zeros of the Riemann zeta function and the eigenvalues of families of random matrices. Further work uncovered deep relationships between random matrix theory and the zeros of L-functions in general. We expand upon previous work to use this connection between Number Theory and Random Matrix Theory to study the low-lying zeros (that is, zeros near the central point) of L-functions. In particular, we use the 2-level density to find upper bounds on the average order of vanishing of families of L-functions at the central point.

Efficient Calculation of RNA Secondary Structures with Terminal Stacking

Nikolaus H.R. Howe

An RNA sequence can adopt an immense number of secondary structures (distinct combinations of base pairs), however is often represented by only a handful of minimum free energy (MFE) microstates. These few MFE microstates paint an incomplete picture of the thermal ensemble of folds of a given molecule. To predict what will be observed in experiments of RNA folding it is necessary to consider the whole thermal ensemble of microstates, not just the MFE. The properties of the thermal ensemble and probabilities of each microstate are described with a partition function sum over all the microstates or a Boltzmann-weighted sample of microstates. In this thesis we build an algorithm to compute both more efficiently.

The multiplicity of secondary structures scales exponentially with length as the often-quoted O(1.8 N ). Additionally, however, because an unpaired base adjacent to a base pair can either stack on the pair or not, for any secondary structure there are also many possible ways of stacking unpaired bases. Here we show that including terminal stacking configurations increases the multiplicity to O(2.09 N ).

The partition function and its multiplicity can be obtained with recursion, so we employ a dynamic programming algorithm, which allows us to sum the contributions of exponentially many states in O(N 3 ) time. Our novel formulation of the recursion relations allows us to recompute the partition function in O(N 2 ) time and to sample a microstate consistent with its Boltzmann probability in O(N) time per sample.

Meta-Analysis of Risk Differences Under Random Effects

Hae-Min Jung

Meta-analysis combines the results of multiple studies to infer an overall treatment effect.  Random Effects methods are popular in dealing with variance between the treatment effects estimated by each study. Of the three most common effect measures for 2×2 contingency tables, the Risk Difference remains the least understood for Random Effects. Existing popular methods are structurally awed and use assumptions inappropriate for the Risk Difference.

We propose a new, unbiased estimate of the between-study variance under minimal assumptions. This new estimate is used to construct a Wilson Score-type confidence interval for the common Risk Difference.  The new method is advantageous over existing methods due to its closed-form solution, lack of distributional assumptions, and flexibility regarding the selection of weights. Simulation studies show that it performs well under both low and high between-study variance.

The Isomorphism and Centralizer Problems for Partially Bounded Transformations

Alexander Kastner

Ergodic theory is the study of measure-preserving transformations which map a measure space into itself. One of the central problems in the field is the isomorphism problem, which asks whether two given transformations are isomorphic. A somewhat related problem is the centralizer problem, which asks which transformations commute with a given transformation. While it can be shown that, in a precise sense, both the isomorphism and centralizer problems are intractable in general, there is hope that a complete characterization may be possible if we restrict our attention to the generic class of rank-one transformations. We investigate these questions for the newly defined class of partially bounded transformations, which encompasses many well-known infinite rank-one transformations such as the infinite Chacón and Hajian-Kakutani transformations. In particular, we establish that the only transformations that commute with a partially bounded transformation T are the powers T n for integers n. Further, we characterize exactly when a partially bounded transformation is isomorphic to its inverse. Finally, we discuss generalizations to rank-one flows.

On Trace Ideals, Duals of Ideals, and Annihilators

Let M be a module over a ring R. The trace ideal of M is an ideal of R obtained from the set of homomorphisms from M to R: it is the sum of the images of each homomorphism in R. We present results that describe the trace ideals of ideals (viewing these ideals as modules over R) satisfying various conditions. We determine several sufficient conditions for an ideal to be equal to its trace ideal. The set of homomorphisms from M to R is called the dual of M. We examine duals of ideals in terms of particular maps contained in the dual, in terms of grade, and in terms of generators of ideals. In addition, we characterize dimension zero Gorenstein rings in terms of their trace ideals. Throughout we explore the rich relationship between trace ideals and annihilators.

Entropy Computation for Measure-Preserving Transformations

Matthew James Quinn

Entropy provides a notion of how random partitions and measure-preserving transformations are by looking at how many bits of information we can expect to gain from an experiment that is represented by them. In this paper, we provide original proofs that lead to showing that the generalized odometer, with an arbitrary sequence of cuts, has zero entropy. We likewise consider the Hajian-Kakutani Skyscraper transformation. However, entropy is traditionally defined on a finite measure space. Therefore, in studying the Hajian-Kakutani Skyscraper transformation, we suggest a new adjustment for entropy to be defined over a space of infinite measure. We then discuss an extension of our arguments to all rank-one transformations.

Human Performance and Aging: A Statistical Approach

John Robert Shuck

Previous studies of aging do not take into account the inherent uncertainty associated with aging across the lifespan. This thesis explores the deterioration of performance times in masters athletes with a new statistical approach. Uncertainty in performance deterioration with age is accounted for by more precise modelling techniques and through construction of empirical confidence intervals. Through the statistical methods proposed in this thesis, it is possible to quantify which age ranges show similar rates of performance deterioration across different masters athletic events. Ultimately, it is found that deterioration is similar in the 55-70 age range across many different sports, indicating the existence of a universal aging mechanism that is not mediated by sport specific selection variables.

New Classes of Orthogonal Polynomials on the Unit Circle and Bernoulli Distributed Verblunsky Coefficients

Andy Yu Zhu Yao

My thesis presents the general theory for orthogonal polynomials on the unit circle (OPUC) and reviews some classic examples of OPUC. I study and characterize new examples of orthogonal polynomials on the unit circle. Furthermore, I prove properties relating Bernoulli random Verblunsky coefficients and the zeros of the orthogonal polynomials.

Generalizations of Multidimensional Continued Fractions:  Tetrahedron and k-Dimensional

Emmanuel Howard Daring

The decimal and continued fraction expansions of a number are periodic if and only if the number is rational or a quadratic irrational, respectively. Multidimensional continued fractions aim to replicate this property with different types of irrational numbers, partitioning a triangle to produce a periodic sequence if the coordinates of the point the sequence describes are at worst cubic irrationals in the same number field. In this paper, we redefine an existing multidimensional continued fraction algorithm which partitions the triangle. This new definition lends itself to being generalized to higher dimensions, partitioning any infinite n-th dimensional simplex to produce periodic sequences when the coordinates of a point are algebraic in the same number field of degree n + 1. We observe this generalization in action for the case n = 3, where the 3rd dimensional simplex is a tetrahedron.

Moves on Übercrossing Projections of Links

Xixi Edelsbrunner

Generally knot and link projections have crossings with two strands passing through. An übercrossing projection of a link L is a projection with exactly one crossing with any number of strands bisecting it. The übercrossing number ü is the least number of loops in any projection of L . We develop moves with which we can travel between übercrossing projections for a fixed knot. We also present a proof for a bound on braid index in terms of übercrossing number for link projections.

Blowing Up Toric Varieites With Multidimensional Continued Fractions

Elizabeth Frank

Because toric varieties are built up from convex geometry, there is a natural connection to be made with triangle partition maps, which are multidimensional continued fraction algorithms. Our motivation to explore this connection is showing that to resolve the curve y p =x q we follow a path of blowups given by the continued fraction expansion of p/q.  Dividing the triangle according to the Triangle Map turns out to be equivalent to blowing up an axis in C 3 . We apply these blowups to resolving singularities of curves. We also discuss these blowups and blowdowns in terms of attracting or repelling curves toward or away from curves defined by a quadratic irrational or a pair of cubic irrationals with a periodic triangle sequence.

Bipyramind Decompositions of Multi-Crossing Link Complements

Gregory Kehne

Generalizing constructions of D. Thurston and C. Adams, we present a dual pair of decompositions of the complement of a link L into bipyramids, given any multi-crossing projection of L . When L is hyperbolic, this gives new upper bounds on the volume of L  given its multi-crossing projection, which empirically approach a constant factor of the volume for typical petal and über knots. Additionally, this construction yields families of immersed surfaces in the complement of L , including a generalization of checkerboard surfaces.

Examining More Sum Than Difference Sets in Multiple Lattices

Lawrence Luo

The definition of a traditional MSTD set is a finite set A ⊂ Z whose sumset, defined by A + A = { a 1 + a 2 : a 1 , a 2 ∈ A } , is larger in cardinality than its difference set A − A , defined by A − A = { a 1 − a 2 : a 1 , a 2 ∈ A } . We can view a MSTD set in two dimensions by making a polytope P whose lattice points form the elements from which a set A is constructed. The sumset and difference sets of A are then calculated by adding or subtracting the coordinates of the lattice points.

Thao Do, Archit Kulkarni, Steven Miller, David Moon ‘16, Jake Wellens, and James Wilcox ’13 explored MSTD sets in R D space with lattice points in Z D , for D > 0, generalizing previous results in Z by allowing the dilation of polytopes in R D . Instead of exploring MSTD sets in R D , we examine the frequency of such sets in the R 2 space specifically.

To observe MSTD sets in two dimensions, we first take the five possible lattices in the Euclidean plane (square, rectangular, rhombic, parallelogramic, and hexagonal) and prove that every convex polytope in one lattice has a “strongly” equivalent convex polytope for each of the four other lattices that preserves its MSTD characteristics.

We investigate and discuss the importance of interior points for preserving the MSTD nature of balanced convex polytopes across lattices, and also discuss how a difference dominant convex polytope remain difference dominant when taking the boundary plus any combination of its interior points.

We also discuss efficient boundary constructions for generating larger MSTD densities, and offer conjectures on optimal boundary constructions for the square and hexagonal lattices.

We conclude with a discussion on the shortcomings of the code used to generate our experimental data.

Generalizing the Minkowski Function Using Triangle Partition Maps

Peter Morton McDonald, Jr.

In this paper, we present two previous attempts at generalizing the Minkowski Question Mark Function before presenting a framework for generalizing ?(x) to a family of 216 multidimensional continued fraction algorithms known as triangle partition (TRIP) maps.  Furthermore, we place these 216 maps into 15 classes whose associated generalization of the Question Mark Function is related by a linear transformation and show for 7 of these classes that this function is singular.

Modeling the Dynamics of Persistence and Extinction in Ecology

Alexander Dolnick Meyer

Mathematical models are invaluable tools for ecologists. A well-constructed model not only holds predictive power, but also matches observations made in the field and sheds light on the mechanisms that underlie the complex interactions between organisms and their environment.  Simulation allows researchers to conduct experiments in silico that would be impractical or unethical to conduct in the field, enabling ecologists and conservationists to forecast the outcomes of environmental management strategies prior to implementation. My investigation explores the mechanisms of species persistence and extinction in two unique examples: the lethal white-nose syndrome (WNS) epidemic decimating New England’s bat populations, and the temporally/spatially synchronized emergences of periodical cicadas. In particular, I use models to determine the efficacy of several WNS control measures and to analyze the mechanisms that allow only one brood of cicadas to persist in a geographical area at the exclusion of all others.

Colorful Graph Associahedra

Given a graph G, there exists a simple convex polytope called the graph associahedron of G whose face poset is based on the connected subgraphs of G. With the additional parameter of color assigned to each subgraph, we define the analogous semi-colorful graph associahedron and show it is a simple abstract polytope. Furthermore, we provide a construction based on the classical permutohedron and various combinatorial and topological properties.

Effective Proofs of Khovanskii’s Theorem in the Integers

Gabriel K. Staton

Khovanskii’s Theorem states that for any finite set A in a commutative semigroup, the sumset nA has polynomial size for sufficiently large values of n, but its proof is ineffective. We give novel and effective proofs of this theorem in finite fields and in the integers, and present some computational work and derived conjectures in higher dimensions.

Rank One Mixing on Levels and a Numerical Analysis of Chacón Type Transformations and the Pascal Transformation

Roger Vargas, Jr.

The rank-one canonical Chacón transformation has been widely studied and is a well understood transformation. It is known that this transformation is Mildly Mixing. The construction of this transformation can be altered in different ways to construct other rank-one (Chacón-type) transformations. Weakly mixing and stronger notions of mixing has not been proven for many of these Chacón-type transformations and the Pascal transformation (our construction of Pascal is not rank-one but is constructed using a cutting and stacking method similar to Chacón). We study the mixing properties of these transformations numerically by employing computational tools. We also give a proof for rank-one transformations that simplifies the condition of mixing for all measurable sets.

Analysis of Technical Stock Trading Strategies

Thomas Andrew Beaudoin, Jr.

Technical analysis has been used by traders for decades, but it has been difficult to examine with the same level of rigor as fundamental analysis due to its highly subjective nature where two traders could see the same data and perform two different actions. In this paper, I evaluate the effectiveness of a few technical strategies that are less subjective and thus could be used algorithmically. I apply these strategies to the 1500 largest US stocks over the period of January 1, 1998 to December 31, 2007. By comparing the gains when testing the strategy over the time period versus the gains when holding the stock from the beginning of the time period, and by comparing the success rate on a stock to stock basis, I find that over the 10 year period one strategy is successful, many unsuccessful yielding potential shorting opportunities, and others yield no difference.

The Crossing Map of Knots

Wyatt Bradley Boyer

The crossing map is a sphere around a knot where each point on the sphere is labeled with the number of crossings one sees in the knot when projected in that direction. Regions of constant value on the crossing map are divided by three types of curves that correspond to the three Reidemeister moves. We explore what each curve determines about the embedding of the knot in space.

Cusp Thicknesses of Checkerboard Surfaces for a Family of Links

Benjamin Demeo

The  cusp thickness  of a surface bounded by a hyperbolic knot  K  is a natural measure of its geodesicity, and depends crucially on the structure of the surface’s limit points in the universal cover  H 3 . We introduce a method for analyzing limit sets of checkerboard surfaces using polyhedral decompositions and apply it to a family of links, obtaining the limit sets and cusp thicknesses. We then apply our results to relevant areas and consider further applications.

Fredholm Theory and Optimal Test Functions for Detecting Central Point Vanishing Over Families of L-Functions

Jesse Benjamin Freeman

The Riemann Zeta-Function is the most studied L-function – its zeros give information about the prime numbers. We can associate L-functions to a wide array of objects. In general, the zeros of these L-functions give information about those objects. For arbitrary L-functions, the order of vanishing at the central point is of particular importance. For example, the Birch and Swinnerton-Dyer conjecture states that the order vanishing at the central point of an elliptic curve L-function is the rank of the Mordell-Weil group of that elliptic curve.

The Katz-Sarnak Density Conjecture states that this order vanishing (and other behavior) are well-modeled by random matrices drawn from the classical compact groups. In particular, the conjecture states that an average order vanishing (over a “family” of L-functions) can bounded using only a given weight function and a chosen test function φ. The conjecture is known for many families when the test functions are suitably restricted.

It is natural to ask which test function is best for each family and for each set of natural restrictions on φ. Our main result is a reduction of an otherwise infinite-dimensional optimization to a finite-dimensional optimization problem for all families and all sets of restrictions. We explicitly solve many of these optimization problems and compute the improved bound we obtain on average rank. While we do not verify the density conjecture for these new, looser restrictions, with this project, we are able to precisely quantify the benefits of such efforts with respect to average rank. Finally, we are able to show that this bound strictly improves as we increase support.

History Dependent Stochastic Processes and Applications to Finance

Nicholas Gardn er

In this paper we focus on properties of discretized random walk, the stochastic processes achieved in their limit, and applications of these processes to finance. We go through a brief foray into probability spaces and sigma-fields, discrete and continuous random walks, stochastic process and Ito calculus, and Brownian motion. We study the properties that make Brownian motion unique and how it is constructed as a limit of a discrete independent random walk. Using this understanding we propose a different kind of random walk that remembers the past. We investigate this new random walk and find properties similar to those of the symmetric random walk.

We look at a well-studied stochastic process called fractional Brownian motion, which uses the Hurst parameter to remember past performance. Using Brownian motion and fractional Brownian motion to model stock behavior, we then detail the famous Black-Scholes options formula and a fractional Black-Scholes model. We compare their performance and accuracy through the observation of twenty different stocks in the market. Finally we discuss under what circumstances is the fractional model more accurate at predicting stock price compared to the standard model and explanations for why this might occur.

Partially Rigid Strictly Doubly Ergodic Rank One Transformations and Related Examples

Rank one cutting and stacking transformations are a useful source of examples in infinite measure spaces. Interestingly, the structure of these cutting and stacking transformations can be reduced to integer sequences, and characterized by combinatorial methods. Our main work is to use these characterizations to develop new classes of transformations meeting certain properties. We develop a transformation which is strictly partially rigid and strictly doubly ergodic (i.e. with non-ergodic Cartesian square), and also give some general conditions for the conservativity of products of cutting and stacking transformations. We also have examples of fully rigid, strictly doubly ergodic transformations. We further the study of power weakly mixing transformations in infinite measure spaces by showing that all (t,q)-type Chacon maps are power weakly mixing, and demonstrating that there are such maps which also have strict partial rigidity but closely bounded recurrence–a result which could not be previously obtained from arguments on genericity. Finally, we come close to answering an open question by Bergelson by showing that there is an infinite measure preserving transformation T with extreme asymmetry: all rectangles sweep out under T, and T has infinite conservative index, but TxT^(-1) is not ergodic.

Imagining a Space of Circular Split Networks

Samantha Petti

Phylogenetic trees are structures used to represent evolutionary histories. A circular split network is a generalization of a tree in which multiple parallel edges signify divergence. We introduce a space of circular split networks and explore its properties. This space, which we call CSNn, is the natural extension of Billera, Holmes, and Vogtman’s tree space to circular split networks. We introduce this space and a topologically rich subspace Cn. We describe the interesting gluing properties of the space. Further, in computing the homotopy of the space, we find a connection between Cn and the real moduli space M0,n.

Partial Rigidity Values on the Levels of  Chacón-type Transformations

Eric George Schneider

We describe a variety of Chacón-Type Transformations based on the Canonical Chacón Transformation that appeared in Friedman in 1970, including finite point extensions. In our search for an alternative proof to Del Junco in 1978 that the Canonical Chacón Transformation is Mildly Mixing we discovered many partial rigidity values over the levels. We provide a method for determining if a partial rigidity value on the levels of the Chacón Transformation is possible as well as establishing an upper bound. This method is then generalized to a class of Chacón-Type Transformations.

Explicit Forms For and Some Functional Analysis Behind a Family of Multidimensional Continued Fractions — Triangle Partition Maps — and Their Associated Transfer Operators

Ilya D. Amburg

The family of 216 multidimensional continued fractions known as known as triangle partition maps (TRIP maps for short) has been used in attempts to solve the Hermite problem [3], and is hence important in its own right. This thesis focuses on the functional analysis behind TRIP maps. We begin by finding the explicit form of all 216 TRIP maps and the corresponding inverses. We proceed to construct recurrence relations for certain classes of these maps; afterward, we present two ways of visualizing the action of each of the 216 maps. We then consider transfer operators naturally arising from each of the TRIP maps, find their explicit form, and present eigenfunctions of eigenvalue 1 for select transfer operators. We observe that the TRIP maps give rise to two classes of transfer operators, present theorems regarding the origin of these classes, and discuss the implications of these theorems; we also present related theorems on the form of transfer operators arising from compositions of TRIP maps. We then proceed to prove that the transfer operators associated with select TRIP maps are nuclear of trace class zero and have spectral gaps. We proceed to show that select TRIP maps are ergodic while also showing that certain TRIP maps never lead to convergence to unique points. We finish by deriving Gauss-Kuzmin distributions associated with select TRIP maps.

Resampling Methods With Applications in Variance Estimation

Shiwen chen.

In point estimation, the true parameter of interest theta of the population distribution F is often estimated by a functional of the empirical distribution of n observations, denoted as q n = q(F n ). In statistical practice, it is important to learn about the sampling distribution and assess the precision of a point estimator by estimating its variance. For many functionals, closed form expression of the sampling distribution is not available. Resampling schemes reproduce samples from the original set of observations. With the help of these reproduced samples, the sampling distribution of q n can be estimated. This thesis explores a set of topics related to resampling schemes. We make contributions in two directions: the proposal of a general class of linearly extrapolated variance estimators as a generalization of the delete-one jackknife variance estimator, and the investigation of resampling schemes for dependent data, in particular, spatial data.

Completions of Unique Factorization Domains With Unique Factorization Modulo a Principal Prime Ideal

Craig Matthew Corsi

We present new work in the theory of complete local rings. Given a complete local ring T with maximal ideal M , and given p Î R , we conjecture that a set of weak conditions is necessary and sufficient to ensure the existence of a local unique factorization domain R such that p Î R and R/pR is also a unique factorization domain. We make significant progress toward proving this claim. Then, given a complete local ring T with maximal ideal M , C a countable set of nonmaximal, pairwise incomparable set of prime ideals of T , and p Î Ç P Î C P , we give necessary and sufficient conditions for T to be the completion of a local integral domain A such that p Î A , and p A is a prime ideal whose formal fiber has maximal elements the elements of C . We also give conditions under which A can be constructed to be excellent.

A Characterization of Trees With Convex Obstacle Number 1 or 2

Philippe Demontigny

A convex obstacle representation of a tree T is a drawing of the vertices of T in the plane with a set of convex polygons so that two vertices are connected by an edge if and only if that edge does not intersect any of the polygons. The minimum number of obstacles required to represent a tree in this way is called the convex obstacle number of the tree. This new description of a graph has steadily gained popularity since its introduction in 2009, and is particularly interesting because of its relationship to visibility graphs, which have been studied extensively and have applications in robot motion planning and architecture. So far, it is known that a representation using only 5 convex obstacles exists for all trees, which implies that the upper bound for the convex obstacle number of any given tree is five. However, not much is known about which trees have a convex obstacle number that is less than 5. In this thesis, we begin to fill this gap by providing necessary and sufficient conditions for a tree to have convex obstacle number 1 or 2. We also provide insights into how one could approach the problem of finding all trees with convex obstacle number 3 or 4.

Modelling and improving Pitching Strategies in Major League Baseball

Carson Eisenach

In Major League Baseball, the bullpen is perhaps the most poorly utilized of a teams resources. Finding better strategies for using the bullpen is very valuable. In this senior thesis, I explore a framework for analyzing pitching strategies in Major League Baseball. The main contributions of this thesis are (1) the development of an extensive set of tools to create the game state data needed to analyze pitching strategies and (2) using the data discovered to develop several models for pitching strategies as well as metrics by which to assess model fit.

A Practical Review of Time-Series Forecasting Using A Large Number of Predictors

Time-series forecasting using a large number of predictors has received increasing attention in recent years. Stock and Watson (1999), Bai and Ng (2002, 2007), among others, have developed techniques to extract relevant information from a large set of forecasting variables with promising results. In this paper, we first study the main theory behind this topic, the diffusion index forecasting model (Stock and Watson, 1999). It estimates unobserved factors nonparametrically by principal components of existing predictors. We have confirmed that the model outperforms the benchmark alternatives in terms of mean squared forecasting error (MSFE). We then explore and present the empirical efficacy of proposed refinements to the model. These include the determination of the number of factors and predictor selection using soft and hard thresholding (Bai and Ng, 2007). Along the way, we will propose and test some potential refinements to the existing methodologies.

Benford’s Law and Fraud Detection

Benford’s Law describes the situation in which the frequency distribution of the first digits in a real-life data set does not follow a uniform distribution. Rather, the probability of a digit d occurring as the leading digit of a data point is the difference between d+1 and d on a logarithmic scale with base 10. This phenomenon has been regularly used by auditors as a tool to detect fraud. The bootstrap is a resampling method which can be used to estimate the sampling distribution of an estimator, first proposed by Efron in 1979.

We apply the bootstrap method to find a way to reduce the number of data points required for effective fraud detection based on Benford’s Law. Oftentimes an auditor may not have access to all the data; a method using a subset of the data for fraud detection makes the auditor’s job possible and potentially saves both human and computational resources. We have found that assuming that a data set of size 5000 or more is either free of manipulation or a result of summing the original values and some values following either a normal distribution or a uniform distribution, we only require 5% of the data to detect potential data manipulation.

Relieving and Readjusting Pythagoras:  Improving the Pythagorean Theorem

Victor Dan Luo

The Pythagorean expectation was invented by Bill James in the late 70’s as a way of calculating how many wins a baseball team should have by utilizing just runs scored and runs allowed. His original formula predicts a winning percentage of RS^2/(RS^2+RA^2), where RS stands for runs scored and RA stands for runs allowed. Although the simplicity of the formula is a thing of beauty, with the development of more advanced baseball statistics it should be possible to enhance the formula such that it gives a more accurate prediction of a team’s wins. Implementing statistics such as ballpark effect as well as accounting for game state factors, we will test to see if it is indeed the case that adjusting the Pythagorean expectation formula gives a statistically significantly better prediction for a team’s wins than the unadjusted formula.

In order to test these adjusted formulas, we will be culling data from the internet, specifically from http://www.retrosheet.org/gamelogs/index.html and espn.com . We will then import this data into R and use our code to manipulate the data, calculating the new adjusted Pythagorean expectation and old Pythagorean expectation by year for each team. Then, using different regression models, we will determine which expectation formula is more accurate.

In addition, it has been shown that we can use a Weibull distribution in order to model run production. The versatility of the distribution is due to the fact that it accounts for three parameters that can be varied to adjust the spread, shift, and scale of the distribution. We will explore whether a linear combination of Weibulls is able to more accurately determine a team’s run production.

Completions of Reduced Local Rings With Prescribed Minimal Prime Ideals

Byron J. Perpetua

A central question in commutative algebra asks when a complete local ring T is the completion of a local subring A, subject to a given set of conditions on A. Arnosti et al. answer the question when T is assumed to contain the rationals and A is required to be a reduced local ring with a finite number of maximal elements in the formal fiber at each of its minimal prime ideals. In this thesis, we construct A so that the number of maximal elements in the formal fiber at each minimal prime ideal is countable instead of finite, and we introduce a new set of necessary and sufficient conditions for T to be the completion of such a ring A, which weaken the requirement that T contain the rationals.

Simultaneous Inference on Margins of Binary Data

Faraz Wasiur Rahman

Simultaneous inference deals with testing several hypotheses that might be related. Techniques in this field control the chances of rejecting one or more of the true hypotheses at a low value like 5%, and then try to reject the remaining false hypotheses with high probability. We will develop and evaluate the performance of a closed testing procedure to analyze the margins of binary data, and explore some applications of the technique in a clinical trial scenario.

Testing Benford’s Law

Jirapat Samanvedhya

Benford’s Law, a phenomenon of the first-significant bias, is often used in fraud and data integrity detection. The application of Benford’s Law uses goodness-of-fit test which typically involves the chi-square, the Kolmogorov-Smirnov, or the Kuiper’s tests. There are some issues with the comparison of these tests: 1) the latter two are designed to test continuous distributions and they are found to be too conservative for discrete distributions 2) we must compare both Type I error and power. This thesis aims to address those issues by using a simulation-based approach to normalize Type I error and bypass the complication with continuity.

We use the Monte Carlo method to compare powers of the Kolmogorov-Smirnov test, the Kuiper’s test and the power-divergence test, which is a family of test statistics that generalizes the chi-square test. We test Benford’s Law against five major discrete distributions (uniform, linear, Poisson, geometric and binomial distributions) and generalize to 2-digit Benford’s Law. We find that the Kuiper’s test is one of the most powerful tests in general. However, when the alternative distribution is very similar to the Benford distribution, the power-divergence test has more power. We then test two real data sets whose distribution of first significant digits visually exhibits Benford behavior. For the AAPL daily trading volume dataset, all tests reject the null hypothesis that it obeys Benford’s Law. For the streamflow dataset, the power-divergence tests rejects the null hypothesis at 95% confidence level, whereas the other tests do not.

A Novel Model for White-Nose Syndrome in Little Brown Bats

David F. Stevens

Bats are important reservoirs for emerging human and wildlife diseases. Certain pathogens that are highly virulent to humans are able to persist in healthy bats and little is known about the mechanisms by which bat immune systems are able to cope with these diseases. White nose syndrome (WNS) is a devastating emerging infectious disease in North American bat populations. In 2006, the first incidence of bats infected with WNS was discovered in a cave near Albany, New York. It has since spread rapidly across eastern North America. WNS is caused by a newly described fungus, Geomyces destructans, that grows on the exterior of hibernating bats. The infection is thought to rouse infected bats from hibernation, depleting essential fat stores and resulting in death by starvation. This disease is forecasted to cause the regional extinction of little brown bats in the northeastern United States, with the potential for serious consequences for ecosystem integrity. In this paper we outline disease control strategies for WNS with the aim of preventing the regional extinction of Myotis lucifugus . For this purpose, we develop a mixed-time SEI model for WNS in  Myotis lucifugus  broken into three stages: (1) roosting, (2) swarming, and (3) hibernation.

Maximal Bipartite Subgraphs of Special 4-Regular Planar Graphs

Sean Sutherland

Graph theorists have long been interested in determining the number of edges included in the largest bipartite subgraph of a given graph. We first provide a simple proof to show that every 4-regular planar graph has a maximal bipartite subgraph containing at least 2/3 of its edges. By applying Hadlock’s [3] procedure for determining bipartite subgraphs of planar graphs, we provide the exact size of the maximal bipartite subgraphs of two special classes of 4-regular planar graphs. We conclude by outlining our attempt to prove that the only graphs for which the maximal bipartite subgraph realizes the 2/3 ratio are the triangular checkerboard graphs.

Limiting Spectral Measures of Random Matrix Ensembles With a Polynomial Link Function

Kirk Swanson

Given an ensemble of N by N random matrices, an interesting question to ask is: do the empirical spectral measures of typical matrices converge to some limiting measure as N tends to infinity? The limiting measures of several canonical matrix ensembles have been well-studied, such as the symmetric Wigner, Toeplitz, and Hankel matrices. It is known that in the limit, the Wigner matrices have a semicircular distribution, the Toeplitz have a near-Gaussian distribution, and the Hankel have a non-unimodal distribution. Although it is not fully understood why, these ensembles exhibit the interesting property that as more constraints are introduced to a patterned random matrix, new limiting measures other than the semicircle can arise. It is natural, then, to explore the question: to what extent will a patterned random matrix continue to have a semicircular limiting eigenvalue distribution? In the following, we explore this question by generalizing the Toeplitz and Hankel ensembles. The resulting matrix ensembles with bivariate polynomial link functions have unique limiting spectral distributions. In specific cases, we establish that when the variables in the polynomial are raised to the same power the limiting measure becomes non-semicircular, but when the variables are raised to different powers the limiting measure remains semicircular.

Primes in Arithmetic Progressions of Polynomials

Samuel Tripp

Dirichlet’s Theorem on Primes in Arithmetic Progressions states that if a and b are coprime, there are infinitely many primes congruent to a modulo b. The proof, however, is quite analytic. Murty and Thain ask for which pairs of integers a and b this can be proved algebraically. They prove that if the square of a is congruent to 1 modulo b, there is an algebraic proof that there are infinitely many primes congruent to a modulo b.

Knowing that the analogue of Dirichlet’s Theorem holds in the function field case, we present results establishing an analogue of the results of Murty and Thain in the function field case as well.

Regression With Missing Data:  An Investigation of the Case with Uniform Predictors and Missingness Related to the Response Variable

Jack T. Ervasti

Missing data is a very important problem in many fields, including the social, behavioral and medicinal sciences. As a result, a number of techniques for analyzing data sets with missing values have been developed and refined in the last few decades. There has also been a significant amount of research done on the bias introduced with different types of missing data when these techniques are performed.

In this paper, I investigate how various types of missingness affect the bias of regression parameters under imputation and complete case analysis. Using simulated data sets, I examine cases with normally and uniformly distributed predictor variables and different types of simulated missingness. I find that uniformly distributed predictors cause bias under different circumstances than normally distributed predictors when missing values are imputed. In particular, I find that if the predictors are uniformly distributed, regression parameters are biased when missingness is related to the response variable and are approximately unbiased when missingness is related to missing values. These results indicate a lack of investigation into missing data with uniformly distributed variables and missingness that is conditional on the response variable. Based on these findings I perform an experiment to gain a deeper understanding of the relationship between types of missingness and the bias of regression parameters in the case with uniform predictor variables.

A Trajectory Smoothing and Clustering Method for the Identification of Potent shRNAs

Alexander H. Greaves-Tunnell

RNA interference (RNAi) is a potent and specific mechanism of gene silencing with extensive applications to research, biotechnology, and medicine. Recently, there has been considerable interest in short hairpin RNAs (shRNAs) as triggers for “programmable” RNAi, due in part to the fact that they enable stable and heritable gene silencing. However, the experimental identification of potent shRNAs is costly and inefficient, and prediction of potent shRNAs for novel targets remains a major challenge. In this paper, we introduce a smoothing and clustering method for data collected from the Sensor assay, the first massively parallel biological procedure for the identification of potent shRNAs. This method is based on a novel treatment of the data as fundamentally longitudinal in nature. We identify a set of roughly 300 top performing shRNAs for the given targets, and conduct preliminary validation based on three sequence and thermodynamic features of known potent shRNAs.S

Benford’s Law and Stick Fragmentation

Many datasets and real-life functions exhibit a leading digit bias, where the first digit base 10 of a number equals 1 not 11% of the time as we would expect if all digits were equally likely, but closer to 30% of the time. This phenomenon is known as Benford’s Law, and has applications ranging from the detection of tax fraud to analyzing the Fibonacci sequence. It is especially applicable in today’s world of ‘Big Data’ and can be used for fraud detection to test data integrity, as most people are unaware of the phenomenon.

The cardinal goal is often determining which datasets follow Benford’s Law. We know that the decomposition of a finite stick based on a reiterative cutting pattern determined by a ‘nice’ probability density function will tend toward Benford’s Law. We extend these previous results to show that this is also true when the cuts are determined by a finite set of nice probability density functions. We further conjecture that when we apply the same exact cut at every level, as long as that cut is not equal to 0.5, the distribution of lengths will still follow Benford’s Law.

Perimeter-Minimizing Tilings by Convex and Non-Convex Pentagons

Zane K. Martin

We study the presumably unnecessary convexity hypothesis in the theorem of Chung et al. on perimeter-minimizing planar tilings by convex pentagons. We prove that the theorem holds without the convexity hypothesis in certain special cases, and we offer direction for further research.

Clustering Time Dependent PITCHf/x Data

Christopher P. Picardo

In this paper I extend the powerful model based clustering framework to data that incorporates an entire time period, specifically single seasons from the PITCHf/x database. Traditional clustering methods are reviewed and described in detail in order to motivate the introduction of model based clustering. In order to apply model based clustering to the time indexed data, a cluster consistency algorithm is proposed that treats the cluster selection problem as equivalent a model selection problem from the supervised learning literature. Finally, the cluster consistency procedure is applied to the PITCHf/x dataset to select the appropriate number of clusters for several pitchers over an entire season. The PITCHf/x season data for two starting pitchers is then analyzed using the cluster movements for the entire season.

Generalizing Nondeterminism for Algebraic Computation Machines

Scott Sanderson

In this thesis we present an introduction to the BSS Machine model, which serves as a generalization of the Turing Machine model of computation. Motivated by the classical equivalence of nondeterministic computation and deterministic verifiability, we develop an extension to the BSS Machine model that preserves important structural features of nondeterministic Turing Machines. We use our machines to develop a new family of relativized complexity classes, and we prove some containment relations between these and the BSS Machine generalizations of P and NP.

The Forest Through the Trees in Multilabel Classification

Benjamin Bradbury Seiler

Traditional machine learning classification algorithms are not suited for statistical classification problems in which an instance can simultaneously belong to more than one class. Such multilabel classification problems have prompted significant research in recent years including a concerted effort to bridge the gap between established classification techniques and this nonstandard framework. Based on such works as recently as Tsoumakas and Katakis [2007] and Vogrincic and Bosnic [2011], the vast majority of novel multilabel classification algorithms are compared to baseline problem transformation techniques using only support vector machines or linear models. In this study, we broaden the pool of potential base learners for problem transformation techniques and discover significant evidence to suggest the superiority of partition tree based methods in many cases, thereby, raising the bar for baseline competitiveness.

Formal Fibers of Height-n Primes and Completions of Complete Intersection Domains

Philip D. Tosteson

Of interest in commutative algebra is the relationship between a Noetherian local ring and its completion. This thesis investigates the relationship between a complete Noetherian local ring (T,M), and Notherian local subrings R of T that have I as their completion. In particular, given an ideal  I of T and a countable collection of prime ideals C of T, we ask whether there exists a subring R, with completion T, such that (I intersect R) is prime, and the formal fiber of R at (I intersect R) has maximal elements precisely C. This question quickly relates to the construction of complete intersection domains whose completions are complete intersection rings and which have specified generic formal fiber. We study this question in several specific special cases, and further discuss progress and a method of attack on a more general case.

Dynamics, Information, and Energy of Morris-Lecar Neurons

We studied the Morris-Lecar model, which is a mathematical model of a motor neuron.  In particular, we studied the mutual information, metabolic energy cost, and energy efficiency of unidirectionally connected Morris-Lecar neurons, and compared our result to the work of Moujahid et al., who studied the mutual information, metabolic energy cost, and energy efficiency of unidirectionally coupled Hodgkin-Huxley neurons.

We found that unidirectionally coupled Morris-Lecar models behave differently from unidirectionally coupled Hodgkin-Huxley neurons in both information transfer and energy efficiency.  Unlike Moujahid et al., we found that among groups of one, five, ten, and twenty postsynaptic neurons, the single Morris-Lecar neuron synchronizes with the presynaptic neuron the best and is the most energy efficient.

On Multiply Recurrent and Manifold Mixing Properties on Infinite Measure Preserving Transformations

Praphruetpong Athiwaratkun

We show an example of an infinite measure preserving transformation such that it is not 2-recurrent and not power weakly mixing. This example demonstrates the striking difference between measure preserving transformations in a finite and sigma-finite measure spaces.

Totally Knotted and Semi-Free Seifert Surfaces

Thomas N. Crawford

In 2005 Osamu Kakimizu determined the Kakimizu Complex, a simplicial complex whose vertices correspond to isotopy classes of Seifert surfaces of a given knot, for all knots with 10 crossings or fewer. We investigate a few properties the surfaces themselves. Specifically we show various combinations of semi-free and totally knotted surfaces, can be embedded in the same knot complement. We restrict ourselves to hyperbolic knots allowing us to also look at the maximal cusp diagrams of the resultant manifold.

Monkemeyer Map Analogues to Stern’s Diatomic Sequence

Noah N. Goldberg Stern’s Diatomic Sequence is a well-studied sequence of integers which stems from continued fractions.  The Monkemeyer Map is a type of multidimensional continued fraction.  We will examine an analogue of Stern’s Diatomic Sequence for the Monkemeyer Map.

Ergodic Properties of TRIP Maps:  A Family of Multidimensional Continued Fractions

Stephanie Jensen

We study the ergodic properties of several of the most relevant TRIP maps, a family of multidimensional continued fractions that encompasses many well-known algorithms. As a first step, we show these maps converge almost everywhere.  From there, we are able to prove ergodicity.

Spaces of Planar Polygons

Brian Li We introduce the space of convex planar polygons with different side lengths. We then consider the side lengths that produce valid linkages as well as the relation of this space to the associahedra and M_0,n.

Choose to Play:  A New Take on the Spatial Prisoner’s Dilemma

Connor McKean Stern The Prisoner’s dilemma is one of the most important models we have to study the evolution of cooperation in a world of self-interested individuals.  Defecting is the only evolutionarily stable strategy, but from previous studies we know that in repeated games and in games with spatial effects cooperating becomes not only possible, but also preferable under certain conditions.  In this paper we explore a new repeated model of the spatial prisoner’s dilemma game where a player can select which opponents to continue interacting with.  By giving players this option we are rejecting the key condition of the repeated game that players cannot avoid interaction, yet we find that this new model shares the same underlying structure of the traditional spatial prisoner’s dilemma.

Stochastic Calculus and Applications to Mathematical Finance

Gregory White In this paper, we review fundamental probability theory, the theory of stochastic processes, and Ito calculus.  We also study an application of Ito calculus in mathematical finance: the Black-Scholes option pricing model for the European call option. We study the development of the model and the assumptions necessary to arrive at the Black-Scholes no arbitrage rational price for a European call option.

We supplement the simple Black-Scholes model by relaxing the assumption that trading can be performed continuously in time, and studying the deviation the Black-Scholes replicating portfolio exhibits from the self-financing characteristic of the continuous-time portfolio.  We term this deviation the cumulative correction of the portfolio and explain in detail its construction.  We study the cumulative correction of Black-Scholes portfolios by performing a numerical analysis of the cumulative correction for outcomes of the stock price stochastic process. While finding a closed form probability distribution representing the cumulative correction proves difficult and we do not pursue that route in this paper, the numerical analysis indicates that the second central moment of the distribution of cumulative corrections decreases as the number of discrete time steps at which the portfolio is rebalanced increases.  Additionally, we analyze the cumulative correction required to replicate the European call option for the historical stock price data series of certain actual stocks, finding examples of a stock that would have required a positive cumulative correction and a stock that would have required a negative cumulative correction.

Spectral Theory for Matrix Orthogonal Polynomials on the Unit Circle

Liyang Zhang

In this thesis, we first introduce the classical theory of orthogonal polynomials on the unit circle and its corresponding matrix representations – the GGT representation and the CMV representation.  We briefly discuss the Sturm oscillation theory for the CMV representation.  Motivated by Schulz-Baldes’ development of Sturm oscillation theory for matrix orthogonal polynomials on the real line, we study matrix orthogonal polynomials on the unit circle.  We prove a connection between spectral properties of GGT representation with matrix entries, CMV representation with matrix entries with intersection of Lagrangian planes.  We use this connection and Bott’s theory on intersection of Lagrangian planes to develop a Sturm oscillation theory for GGT representation with matrix entries and CMV representation with matrix entries.

A Study of Hitting Times for Random Walks on Finite, Undirected Graphs

Ariel Joseph Binder

This thesis applies algebraic graph theory to random walks.  Using the concept of a graph’s fundamental matrix and the method of spectral decomposition, we derive a formula that calculates expected hitting times for discrete-time random walks on finite, undirected, strongly connected graphs.  We arrive at this formula independently of existing literature, and do so in a clearer and more explicit manner than previous works.  Additionally we apply primitive roots of unity to the calculation of expected hitting times for random walks on circulant graphs.  The thesis ends by discussing the difficulty of generalizing these results to higher moments of hitting time distributions, and using a different approach that makes use of the Catalan numbers to investigate hitting time probabilities for random walks on the integer number line.

n-Level Densities of the Low-Lying Zeroes of Quadratic Dirichlet L-Functions

Jake Levinson

The statistical distributions of zeros of L-functions can be used to study prime numbers, elliptic curves and even the ideal class groups of number fields. L-functions have been studied in connection with random matrix theory, which provides easier methods of computing these distributions.  One statistic, the n-level density of low-lying zeros for a family of L-functions, measures the distribution of zeros near the central point s = 1/2. The Density Conjecture of Katz and Sarnak states that the n-level density for an L-function family depends on a classical compact group associated to the family.  We extend previous work by Gao on the n-level densities of quadratic Dirichlet L-functions. Our main result is to confirm up to n = 6 that, for test functions of suitable support, the density is as predicted by random matrix theory.  We also consider a (conjectural) combinatorial identity for certain Fourier transforms of the test functions which, if true, would help in extending the result to all n.

Chains of Rings with Local Formal Fibers

Sean Carlos Pegado

Let R be a local (Noetherian) commutative ring with unity. If R is complete, its structure is understood; however, less is known if R is not complete, and thus the relationship between a ring and its completion is a subject of current research. To this end, previous work has begun to investigate the relationship between prime ideals of a ring and the prime ideals of its completion. We generalize these results to chains of rings that share the same completion.

Optimal Control of the Generalized Moving Point Mass Dynamic

Thuy Vinh Pham

We study the generalized time-optimal control problem where the underlying dynamic is a moving point mass under Newtonian mechanics with acceleration and velocity constraints. The optimal control of this control problem coincides with the viscosity solution of a specific partial differential equation of Hamilton-Jacobi type. Using the dynamic programming approach, we derive the associated Hamilton-Jacobi-Bellman equation and obtain its numerical solution with a semi-Lagrangian discretization scheme.

Robust Regression Boosting

Ville Satopaa

In 2010 Long and Servedio suggested that boosting algorithms that are based on convex loss functions are flawed in a sense that they cannot tolerate outliers.  Inspired by Long and Servedio’s observation, this undergraduate thesis introduces a novel regression boosting algorithm that is based on a non-convex loss function.  First, several properties of this algorithm are stated and proven.  Second, experimental evidence showing that this algorithm is highly robust in the presence of outliers is given.

Generic Formal Fibers

Let T be a complete local ring.  We present necessary and sufficient conditions for which there exists a local integral domain A, a subring of T, whose completion is T with a generic formal fiber that has countably many maximal elements.  We also present results on the elements we can adjoin to this integral domain A.

Geometric Degree of 2-Bridge Knots

Jacob Wagner

In 1987, Kuiper introduced geometric degree alongside superbridge index, but degree has been studied far less than superbridge. In this thesis, we calculate degree for all 2-bridge, 4-superbridge knots. Then, we modify the definitions of degree and a related invariant, thin position, to generate new measures.

Sturm-Liouville Oscillation Theory for Differential Equations and Applications to Functional Analysis

Zhaoning Wang

We study the connection between second-order differential equations and their corresponding difference equations.  With this connection in mind, we investigate quantitative and qualitative properties of the zeros of the solutions of differential/difference equations and of the eigenvalues of the associated Jacobi matrices.  In particular, we study various applications of the Sturm-Liouville Oscillation Theory to differential equations and spectral theory.

The Limiting Spectral Measure for the Ensemble of Generalized Real Symmetric Block m-Circulant Matrices

Wentao Xiong

Given an ensemble of N x N random matrices with independent entries chosen from a nice probability distribution, a natural question is whether the empirical spectral measures of typical matrices converge to some limiting measure as N tends to infinity. It has been shown that the limiting spectral distribution for the ensemble of real symmetric matrices is a semi-circle, and that the distribution for real symmetric circulant matrices is a Gaussian. As a transition from the general real symmetric matrices to the highly structured circulant matrices, the ensemble of block m-circulant matrices with toroidal diagonals of period m exhibits an eigenvalue density as the product of a Gaussian and a certain even polynomial of degree 2m-2. This paper generalizes the m-circulant pattern and shows that the limiting spectral distribution is determined by the pattern of the i.i.d.r.v. elements within an m-period, depending on not only the frequency at which each element appears, but also the way the elements are arranged. For an arbitrary pattern, the empirical spectral measures converge to some nice probability distribution as N tends to infinity.

Evolutionary Dynamics on Weighted Edge Graphs with Structural Balance Conditions:  A Generalized Model of Social Networks

Christophe Dorsey-Guillaumin

We present a generalized model of social networks using a weighted-edge graph with dynamics.  Specifically, each edge in this model evolves in accordance with its membership in one or more triads, or edge triples; the stability of these triads will be defined by a dynamical interpretation of a variation of Balance Theory. We analyze this system in the single triad and general case, find several types of  fixed points in the system, and point to directions for further study.

Non-Orientable Heegaard Splittings

Andrew Scott Lee

Certain decompositions of 3-manifolds are called Heegaard splittings.  Starting from the figure eight knot, we exhibit an infinite class of hyperbolic examples in the non-orientable case derived from knot complements and describe some splittings of surface bundles over the circle.

From Doodles to Diagrams

Noel F. MacNaughton

Consider a diagram as a four-valent graph on a sphere, that is, a graph where every vertex is adjacent to exactly four edges. We look at the faces of these diagrams as being m-gons when the face has exactly m edges. We consider what types of diagrams can be drawn that have their only faces be 2-gons or n-gons for some n≥5, how many of these diagrams exist, and how many components they can have. We then consider the same information for the case when all faces are either 3-gons or n-gons for n≥5.

Modeling Convolutions of L-Functions

Ralph Elliott Morrison

A number of mathematical methods have been shown to model the zeroes of L-functions with remarkable success, including the Ratios Conjecture and Random Matrix Theory. In order to understand the structure of convolutions of families of L-functions, we investigate how well these methods model the zeros of such functions.  Our primary focus is the convolution of the L-function associated to Ramanujan’s tau function with the family of quadratic Dirichlet L-functions, for which J.B. Conrey and N.C. Snaith computed the Ratios Conjecture’s prediction. Our main result is performing the number theory calculations and verifying these predictions for the one-level density up to square-root error term. Unlike Random Matrix Theory, which only predicts the main term, the Ratios Conjecture detects the arithmetic of the family and makes detailed predictions about their dependence in the lower order terms. Interestingly, while Random Matrix Theory is frequently used to model behavior of L-functions (or at least the main terms), there has been little if any work on the analogue of convolving families of L-functions by convolving random matrix ensembles. We explore one possibility by considering Kronecker products; unfortunately, it appears that this is not the correct random matrix analogue to convolving families.

Chains of Excellent Reduced Local Rings

Bolor Turmunkh Let (T,M) be a complete local ring with dimension at least one which contains the rationals, C a  finite set of incomparable non-maximal prime ideals of T.  We find sufficient conditions for T to be the completion of an excellent integral domain B0 with semilocal generic formal fiber ring with maximal ideals the elements of C, and excellent reduced local rings B1, B2 … Bk such that B0 is contained in B1 which is contained in B2 and etc.  We also require that B1,…Bk have semilocal formal fiber rings, whose maximal ideals we can prescribe.  In other words, we find a relatively weak sufficient conditions such that for a given complete local ring T we have an excellent integral domain B0 and a chain of excellent reduced local rings B1,…,Bk such that all of them complete to T and we have a containment as well as the properties concerning the formal fiber rings.

Semilocal Formal Fibers

Domenico Aiello

Let (T,M) be a complete local Noetherian ring, C a finite set of pairwise incomparable nonmaximal prime ideals of T, and p ϵ T a nonzero element.  We find necessary and sufficient conditions for T to be the completion of integral domains A and B where A ⊆ B, the generic formal fiber of A is semilocal with maximal ideals the elements of C, and pB is a height one prime ideal of B whose formal fiber is semilocal with maximal ideals the elements of C.  We also show that given a complete local ring of the form T = k[[x1, x2,…, xn]]/I, where after proper reordering of the indeterminants, I ⊆ (xk+1, xk+2,…, xn)T with k < n and given a prime ideal Q = (x1, x2,…, xl)of T, k ≤ l < n, there exists a domain A such that  = T and (x1, x2,…, xk)A is a height k prime ideal of A whose formal fiber is local with maximal ideal Q.

Unknotting Tunnels and Geodesic Heegaard Splittings of Hyperbolic 3-Manifolds

Karin Knudson

Using the geometric structure associated with the complement of a hyperbolic knot, we present several conditions that are sufficient to ensure that a given arc in the knot complement is an unknotting tunnel.  Then, we apply similar techniques to determine when a closed geodesic in a closed hyperbolic 3-manifold can be used to generate a Heegaard splitting of that manifold.

The Soap Bubble Problem on the Sphere

Edward Souder Newkirk

We consider the soap bubble problem on the sphere S2, which seeks a perimeter-minimizing partition into n regions of given areas.  For n = 4, it is conjectured that a tetrahedral partition is minimizing.  We prove that there exists a unique tetrahedral partition into given areas, and that this partition has less perimeter than any other partition dividing the sphere into the same four connected areas.

Class Number Divisibility in Quadratic Fields

Natee Pitiwan

Number fields and function fields are finite algebraic extensions of the field of rational numbers and the quotient field of polynomials over finite fields, respectively.  To each number field and function field we associate the class group and class number, which contain information on how close the ring of integers of the field is to being a unique factorization domain.  It is known that infinitely many number fields and function fields have class number divisible by a given integer.  The Reflection Theorem by Scholz shows that there are infinitely many corresponding pairs of real and imaginary quadratic number fields with class number divisible by 3.  Based on Komatsu’s generalization of this result, we prove an analogue for function fields.  Another related question on class groups is the n-rank of the group.  It has been shown that there are infinitely many quadratic number fields with 3-rank at least 2, but less is known about other n-ranks.  We consider the case of 5-rank and show a partial result on class number divisibility.

Isoperimetric Regions on a Weighted 2-Dimensional Lattice

Deividas Seferis

In this thesis we investigate isoperimetric regions in the 1st quadrant of the two-dimensional lattice, where each point is weighted by the sum of its coordinates.  We analyze the isoperimetric properties of five types of regions located in the first quadrant of the Cartesian plane:  squares, rectangles, quarter circles, diamonds, crosses and triangles.  To compute volume and perimeter of each region we use summation and integration methods which give comparable but not identical results.  Among our candidates we find that the diamond has the least perimeter for given volume.

A Compactification of the Configuration Space of Particles on a Graph

We generalize the compactification of configuration spaces and tilings from points on one-manifolds to points on graphs.  The compactification of the real moduli space, M_0n(R), is combinatorially equivalent to the compactification of the configuration space of n – 3 particles on a circle with three marked points, and this equivalence provides a tiling of [M]_0n(R) by associahedra.  We find a tiling of the compactification of the configuration space of n particles on an arbitrary graph by polytopes such as associahedra and cyclohedra.

Extensions of Extremal Graph Theory to Grids

Bret Thacher

We determine an upper and a lower bound for the number of edges that a grid graph with no rectangles can have.

On Panti’s Generalization of the n-Dimensional Minkowski Question-Mark Function

A real number x is a quadratic irrational if and only if it has an eventually periodic continued fraction expansion. This property led Hermann Minkowski to construct a function that can be seen as the confrontation of regular continued fractions and the alternated dyadic system within [0,1]. The function has zero derivative almost everywhere, and is continuous and strictly increasing. In this this, we discuss the n-dimensional analogue of Minkowski’s function as defined by Giovanni Panti.

The Number of Summands in the Ostrowski Alpha Numeration

Wasin Vipismakul

One of the beautiful facts in number theory is that every natural number can be expressed uniquely as a sum of non-consecutive Fibonacci numbers. In fact, we can generalize this result to a more general sequence, and we call such sum the Ostrowski alpha-numeration, where alphia is a root of some quadratic polynomial. A natural question to ask is “How many non-zero terms, in average, are required in the sum?” We will define what it means to be “average” and compute it for some class of alpha.

On Equivalence Relations on Sequence Spaces

Paul Alexander Woodard

Given a sequence space S, we can define an equivalence relation ~ x on S by (x n ~ x (y n ) for (x n ),(y n ) in S if and only if (y n -x n ) is in X, where X is a subspace of S, such as 1 1 , the space of absolutely summable sequences, or c 0 , the space of sequences converging to 0. The quotient space S/~ x is also a vector space, so we can study the linear functionals which act on it. To this end, we examine infinite matrices whose rows, as elements of the dual space of X converge weak* to (0).

A Numerical Analysis of the Spectrum of the Almost Mathieu Operator

In 1981, Marc Kac offered ten martinis to anyone who could prove that the spectrum of the almost Mathieu operator is a Cantor Set. This problem, which became known as the Ten Martini Problem, remained unsolved until 2005, when Avila and Jitomirskaya published their solution. Although the theoretical solution now exists, it is difficult to develop an intuitive understanding of these results. In this study we present a numerical analysis of the spectrum of the almost Mathieu operator, using the software Mathematica , in an attempt to better understand the implications of these results.

The Spectrum of the Random Schrodinger Operator

Irina Yurieva Zhecheva

Random Schrodinger operators have important applications in physics. We use results from ergodic theory, probability, and functional analysis to find about the spectrum of the random Schrodinger operator. Specifically, we show why the spectrum of the random Schrodinger operator is deterministic.

Slicing Polyhedra: Searching for Convex Cross-Sections

Katherine Baldiga

We develop a method for determining whether or not it is possible to slice a polyhedron and produce only convex cross-sections. This slicing takes the form of rotating and translating a slicing plane over the polyhedron in a continuous sweep. Then, we address whether this can be done using a slicing plane with a fixed normal direction. Our methods use three-dimensional dualization techniques, where solutions appear in the form of paths through the dual. We improve upon previous methods used to slice polygons into one-dimensional cross-sections by incorporating more geometric information into the dual. Finally, we reveal how these improvements yield more insightful solutions not only to the convex cross-section question but also to other types of decomposition questions.

Weighted Blow-Ups of the Braid Arrangement

Colin D. Carroll

We use compactifications of the braid arrangement as a motivation to weight points on a line and define a way to use these weights to produce building sets. We define two operations on bracketings on a path with /n/ nodes which describe the poset structure of truncated simplices by weighting points in the configuration space. We provide both global and local descriptions of the spectrum of blow-ups of the braid arrangement.

Growth and Combinatorial Properties of the Triangle Sequence

Shea Daniel Chen

Triangle sequences are a type of multi-dimensional continued fraction. We investigate growth rates of the denominators in triangle sequences, in analog to the growth rates of the denominators in continued fractions. In particular we look at the analog of the Euler totient function for triangle sequences, which gives us the number of points in the triangle sequence given a denominator. We also study the distribution of denominators for special sets of triangle sequences. Finally, we present a combinatorial representation for triangle sequences.

Alpha-Regular Stick Knots

Diana Davis

A stick knot is a closed chain of line segments attached end to end. An alpha-regular stick knot has unit-length segments where the angle at each vertex is the same, some angle that we call alpha. If we have found an example of a stick knot that is very nearly alpha-regular, with sticks that are very close to unit length and angles that are very close to alpha, we would like to say that a stick knot exists of the same knot type, where the sticks are exactly unit length and the angles are exactly alpha. Previous work has proved this result for regular stick knots (with unit-length sticks but different angles) and for very specific cases of alpha-regular stick knots. We prove this result in full generality, with one small caveat. We also provide some new results for the trivial knot and some general discussion of alpha-regular knots.

Simultaneous Confidence Interval Estimation for Multivariate Binary Data

Douglas Robert Hammond

We first consider the different methods which are currently used to form confidence intervals for the true proportion of univariate binary distributions. Then, we consider the methods which are currently used to form simultaneous confidence intervals for the true proportions of multivariate binary distributions. Next we compare the relative performance of these latter methods over a range of marginal probabilities and correlation structures. Finally, we evaluate the problems of Peter Westfall’s iterative bootstrap method for forming simultaneous confidence intervals, provide suggestions about how to deal with these problems and propose and evaluate a slightly different form of Westfall’s method.

On Sensitivity in Topological Dynamics

Jennifer Elizabeth James

Sensitive dependence on initial conditions captures the notion that small differences between initial states result in great distinctions between eventual behaviors. In this work I discuss several topological properties and distinct concepts of chaos. I also examine results that imply sensitivity on compact spaces and prove that various properties imply the sensitivity of continuous maps on locally compact spaces.

A Classification of Spanning Surfaces for Alternating Links

Thomas Kindred

A surface spans a link if it has boundary equal to the link. We present a new construction that gives spanning surfaces for any link, and we prove that this construction produces all possible spanning surfaces for alternating links, up to a certain equivalence. As corollaries, we present easy methods for determining the cross-cap number and overall (orientable or non-orientable) genus for any alternating link.

Partition Congruences and Modular Forms

Ross Daniel Kravitz

The partition function of a positive integer n counts the number of different ways of writing n as a sum of positive integers. It is a purely combinatorial object. Modular forms are holomorphic functions on the upper half plane satisfying a certain growth condition and functional equation, and their theory is part of complex analysis. We’ll look at how the theory of modular forms can be used to study congruence properties of the partition function, an area of research initiated by Srinivasa Ramanujan. In particular, we’ll look at congruence properties modulo 2 and 3, which strangely seem to be the most difficult primes to get a handle on.

Descriptive Dynamics of Borel Endomorphisms and Group Actions

Kathryn Anne Lindsey

This thesis explores the dynamical properties of Borel endomorphisms and group actions on Polish spaces equipped with their -algebra of Borel sets, and obtains descriptive versions of key results from measurable dynamics. Sets in WT, the ideal consisting of all countable unions of wandering sets, are considered “trivial,” and most results are proven to hold modulo a set in WT. Original results presented here include descriptive analogues of the Poincare Recurrence lemma, Rohlin lemma, and Birkhoff Ergodic Theorem for Borel endomorphisms, as well as generalizing the notions of the Shelah-Weiss ideal, saturation, compressability, decomposability, and the Hopf ideal to the case of Borel endomorphisms. A similar theory is developed for Borel actions of countable groups.

Chains of Rings with Local Formal Fibers at Principal Prime Ideals

Myron Minn-Thu-Aye

Given a local ring R, we can define a metric on R and complete the ring with respect to this metric. While it is difficult to determine the properties of rings in general, we know much more about the structure of complete local rings. Therefore, we can study a local ring by considering its relationship to its completion. In particular, suppose we are given a complete local ring (T,M). Let P1, P2, …, Pn be a chain of nonmaximal prime ideals of T with Pi contained in Pj for all i < j. Let p be a regular element of T contained in P1. We give necessary and sufficient conditions for there to exist a chain of local domains Bn, B(n-1), …, B1 where Bi is contained in Bj for all i > j such that p is contained in Bn, each Bi completes to T and the formal fiber of each Bi at pBi is local with maximal ideal Pi.

Least-Perimeter Partitions of the Sphere

Conor Quinn

We consider generalizations of the honeycomb problem to the sphere S2 and seek the perimeter-minimizing partition into n regions of equal area. We provide a new proof of Masters’ result that three great semicircles meeting at the poles at 120 degrees minimize perimeter among partitions into three equal areas. We also treat the case of four equal areas, and we prove under various hypotheses that the tetrahedral arrangement of four equilateral triangles meeting at 120 degrees minimizes perimeter among partitions into four equal areas.

Spectral Properties of Random Unitary Band Matrices

Brian Zachary Simanek

Verblunsky’s Theorem states that there is a one to one correspondence between sequences of complex numbers in the unit disc and nontrivial measures on the unit circle. Given any nontrivial measure on the unit circle, we can obtain a sequence of orthogonal polynomials that obey a recurrence relation involving a sequence of numbers in the unit disc, the so-called Verblunsky coefficients. In 2005, Stoiciu proved that if the Verblunsky coefficients are i.i.d. random variables distributed uniformly on the disc of radius less than 1, then the asymptotic distribution of the eigenvalues of the corresponding CMV matrix is almost surely Poisson. The first part of this thesis is devoted to proving the same result, but with the Verblunsky coefficients coming from different distribution that is more concentrated at the origin. The second part of this thesis studies a different type of unitary band matrix that we call a “Joye Matrix.” Using known methods, we can obtain much information about the spectral properties of these matrices. We conclude with a proof of Aizenman’s Theorem for Joye Matrices when the distribution of the phases is any one of a very large class of distributions. This is a major step towards proving that the asymptotic distribution of the eigenvalues of these matrices is also Poisson.

A New Multi-Strategy Approach to Ensemble Classification

Although classification techniques can be very powerful on their own, they perform even better when combined. An aggregated model of multiple classifiers is called an ensemble, and current research focuses on finding ensemble methods that are effective over a wide variety of classification problems. For an ensemble to be effective, its base classifiers must be accurate and diverse, but it is difficult to increase one of these properties without decreasing the other. In this thesis, we explore how a heterogeneous ensemble, one that combines a variety of different classification strategies, might allow both diversity and accuracy to increase, resulting in a higher-performing ensemble. We examine a new hybrid model which we call 7-Stack, and find that its predictions are consistently more accurate than the predictions of other ensemble methods.

Implementation of Stochasticity in Differential Equation Models with Applications to Modeling Hematological Diseases

Christina Brakken-Thal

Biological models have been criticized for not being able to take into account stochasticity found in biological data, particularly variations in time delays. In this paper, I show how to implement stochasticity, using the Naor process, into time delays in discrete differential equation models. The Naor process was implemented in the red blood cell model of cyclic hemolytic anemia proposed by Mahaffy, Belair, and Mackey in 1998. The introduction of stochasticity into the red blood cell model significantly decreases the size of the red blood cell cycles and the size of the period of the cycles. The introduction of stochasticity also has a minor effect on the bifurcation point of where the cycles start to occur. These results indicate that stochasticity is an important consideration when trying to model the size and the period of cyclic diseases.

Excluded Blocks in Cellular Automata

James Clayton Kingsbery, Jr.

Cellular Automata (CA) are systems that have locally defined behavior that are capable of exhibiting complex global behavior. In this work, we find very very tight bounds for the shortest excluded blocks of one particular type of CA, which is believed to have the longest such block possible. This bound is drastically tighter than that found in any previous work. We go own to look at consequences of this result.

Isoperimetric Regions in Spaces

Michelle D. Lee

We examine the least-perimeter way to enclose given area in various spaces including some spaces with density.

The Honeycomb Problem on Hyperbolic Surfaces

Vojislav S. Sesum

Assuming a certain conjectured Polygonal Isoperimetric Unequality, we prove that a valence three tiling of a compact hyperbolic manifold by regular N-gons is parameter minimizing. We prove the Polygonal Isoperimetric Inequality for some special cases and give some negative computational evidence for other cases.

The Stick Number of Torus Knots

Todd Brooks Shayler

What is the least number of sticks glued end-to-end needed to construct a given knot K? What is the least number of sticks in any projection of K? These invariants are known as the stick number and projection stick number, respectively. Are there embeddings of stick knots realizing the stick number such that we can project into some plane, causing half of the stick to disappear? We find such embeddings of (p,2p+1)-torus knots where one less than half of the sticks are parallel!

Flat Folding with Thick Paper

Computational origami has thus far concerned itself only with paper that was infinitely thin. We explored new issues and possibilities when a thickness is assigned to the paper, such as folding models, combinatorics regarding the diameter of the half-circles around folds, and the phenomenon known as creeping in both the 1D and 2D cases with thickness.

Simultaneous Interval Estimation for Multivariate Normal and Binary Data

We first look at different methods to construct simultaneous confidence intervals for the mean values of multivariate normal distributions. We propose a computer intensive numerical method that produces shorter intervals than the traditional analytical methods. We then extend these methodologies to multivariate binary data. Based on the binomial probability function, we again propose a numerical method to produce shorter intervals.

Diophantine Approximation through Nonsimple Continued Fractions and Planar Curves

Nicholas Sasowski Yates

Here we introduce an explicit function whose graph is a smooth curve that spirals in to the golden ratio phi and crosses the x-axis at precisely the best rational approximates to phi. We then analyze the structure of this Golden Diophantine Spiral. In particular, we determine its limiting proportions, through which we discover a connection between our curve and the well-known Golden Rectangle. We extend our results and define Diophantine Spirals for a large class of real quadratic irrational numbers. We then examine two relatively-unexplored continued fraction representation systems, focusing especially on the expansions of real quadratic irrationals. It is well-known that a number is a real quadratic irrational if and only if its simple continued fraction is eventually periodic. Here we show that, with a fixed integer numerator, all quadratic irrationals can be written periodically with a period of length one. We also explore Diophantine approximation issues within the context of these new expansions. We further investigate whether a similar period-one expansion holds for a system of non-simple continued fractions in which each numerator depends on the previous denominator. Using the dynamics of a related map to study this system, we offer preliminary results and conjectures in this direction, and place these in context with what is currently known.

Helical Structures

Stephen Savinar Moseley

We explore the structural properties of a class of stable structures resembling triple helices. We assume a simplified physics model, and observe an ideal system as it settles. By changing the relative sizes of elements and varying the properties of the rules that define the system’s dynamics, we identify which systems assume regular, stable configurations. We further test stability by applying Brownian perturbations and stretching settled configurations to observe how quickly they resettle. Given the final range of variables that yield stable systems, we compare our structures to the ideal physical characteristics of the collagen protein (which forms a regular triple helix) and hypothesize how the differences between the rules of our simulation and those in nature cause our stable systems to differ from collagen.

Juggling Braids, Links, and Artin Groups

We study the SITESWAP notation used by jugglers and mathematicians for denoting juggling patterns. We construct a map from the space of juggling patterns to links, and prove that this map is onto. In other words, all links can be juggled. We extend this to other juggling patterns that arise from alternate Artin groups.

On Diophantine Approximation Along Algebraic Curves

Ashok Pillai

Building on the previous work of Carsten Elsner from 2001, here we discover a method for approximating almost all positive real numbers by integer points that lie on homogeneous algebraic curves of degree two. We first examine circles and ellipses as special cases before generalizing our work to produce a result for all symmetric homogeneous quadratic curves. Next we extend this generalization to all homogeneous quadratic curves. Finally we employ our methods to approximate certain U-numbers by rational points on singular cubic curves.

Two-Cycles in Three-Dimensional Space

Jordan Rodu

Two-Cycles are approximations of stationary trajectories of flows under probabilistic control, formed when two flows are anti-parallel at a particular point. We know what these two-cycles look like in two dimensional space. In this paper, we will investigate the structure and conditions of two-cycles in three dimensional space. Specifically, we show that locally the locus of points in which flows are anti-parallel is a curve, and that two cycles that approximate these points form a two parameter family of curves.

Class Groups of Function Fields and the Decomposition of Irreducibles in Field Extensions

Matthew P. Spencer

Let n be an integer greater than 2 and suppose S, T and U are pairwise disjoint finite sets of monic irreducible polynomials in Fq (T). We construct infinitely many quadratic function fields K of degree m such that n divides the size of the class group of K, and such that polynomials in S split completely, polynomials in T remain inert, and polynomials in U are totally ramified in K. We present further results concerning higher degree extensions and class groups of high n-rank.

Triangle Sequence Revisited: An In-Depth Look at Triangle Iterations

Christopher Stine Calfee

Purely periodic triangle sequences correspond to cubic irrationals alpha and beta. We will show a variety of methods for finding the irreducible cubic polynomials corresponding to both alpha and beta. Finally, we will explore some of the interesting polynomials which emerge from the sequences that are purely periodic of periodicity length one.

Minimal Blow-ups of Spherical Coxeter Complexes and their Homotopy

Eric Hershel Engler

The goal of my thesis is to find a presentation for the fundamental group of projective spherical Coxeter complexes with minimal blow-ups. It is based on work by Davis, Januszkiewicz and Scott (DJS), who prove that the fundamental group is the kernel of a map p from a group OW that acts on the universal cover of the space onto the underlying group W. DJS prove this result for abstract systems, and thus translating their work is non-trivial, in fact very difficult. We translate their work into the language of graph-associaheda developed by the SMALL 2004 configuration spaces group and specifically compute OW and p. Given these computations, we calculate the fundamental group of these spaces (through dimension six) using java code and a computational algebra package called GAP. From these results, we develop a conjecture for the first homology group.

Double Bubbles in S3, H3, and Gauss Space

Neil Reardon Hoffman

This thesis is the near completion of work done by the 2001-2003 Geometry Groups to prove the double bubble conjecture in the three-sphere S3 and hyperbolic three-space H3 in the cases where we can apply Hutchings theory: in S3, both enclosed volumes and the complement occupy at least 10% of the volume of S3; in H3, the smaller volume is at least 85% that of the larger; And in Gauss space Gm for three-equal-volume double bubbles. A balancing argument and asymptotic analysis reduce the problem in S3 and H3 to some computer checking. The computer analysis has been designed and fully implemented in S3. In H3, it has been only partially implemented.

Completions of UFDs with Semi-Local Formal Fibers

David Jensen

Let (T,M) be a complete local ring such that |T/M| = |T|. Given a finite set of incomparable non-maximal prime ideals C of T, we provide necessary and sufficient conditions for T to be the completion of a local UFD A with semi-local generic formal fiber with maximal ideals the elements of C. We also prove an extension of this result where A contains a height one prime ideal with semi-local formal fiber with maximal ideals the elements of C. In addition, we discuss the possibility of forcing our UFD A to be excellent.

Identifying Best Rational Approximations Through Sharp Diophantine Inequalities

Kari Frazer Lock

Using the theory of continued fractions, we produce a new sharp Diophantine inequality involving an irrational number and a rational approximation to that number, such that the only solutions are precisely all the best rational approximates to the given irrational number; that is, the complete list of its convergents. This work generalizes and extends previously known results appearing in the literature. We also identify the best rational approximates when simultaneously approximating a finite number of generalized golden ratios in the same quadratic field.

Rotating Linkages in a Normed Plane

Jonathan Lovett

In this paper we examine the implications of rotating linkages in generalized norms. We prove that fully rotating a rhombus with both diagonals implies that the norm is linearly equivalent to Euclidean or that the triangle has a certain exceptional property. We also demonstrate that the same is implied by full rotation of some non-exceptional isosceles triangle with median or right triangle with median. In addition, we prove that all triangles can be fully rotated in any norm, and that that rotation is continuous if the norm is strictly convex.

Totally Geodesic Seifert Surfaces in Hyperbolic Complements of Knots in 3-Manifolds

Aaron Daniel Magid

A rich class of hyperbolic 3-manifolds can be represented as the complement of a knot or link in a closed orientable 3-manifold. For these cusped manifolds, we are interested in finding totally geodesic Seifert surfaces, surfaces whose boundary is the knot or link. We consider knot complements for knots embedded in Euclidean 3-manifolds, spherical 3-manifolds, and S2 x S1. We show that all of the closed Euclidean 3-manifolds contain a hyperbolic knot with totally geodesic Seifert surface. Additionally, we show that S2 x S1 and all lens spaces L(p,q) contain a hyperbolic knot with totally geodesic Seifert surface. Also, we give examples of some immersed totally geodesic surfaces in knot complements in the 3-sphere.

The Farey-Bary Map Revisited

Andrew Noah Marder

Two generalizations of the Minkowski ?(x) function are given. As ?(x) maps quadratic irrationals to rational numbers, it is shown that both generalizations send natural classes of pairs of cubic irrational numbers in the same cubic number field to pairs of rational numbers. It is also shown that these functions satisfy an analog to the fact that ?(x), while continuous and increasing, has derivative zero almost everywhere. Both extend earlier work of Beaver-Garrity on the Farey-Bary map.

A Triangle Sequence Pell Equation

Michael T. Baiocchi

Using triangle sequences, a multi-dimensional continued fraction algorithm, this paper develops a higher-dimensional version of the Pell Equation. The set of solutions to this Pell-Analog has the same structure as the solution set to the original Pell Equation. Further, this paper explores the connection both Pells share with the units of particular fields.

Characterization of Completions of Domains with Semi-Local Generic Formal Fiber

Philippa L. Charters

In this paper, we prove the following characterization of the completion of a domain with given generic formal fiber: Let (T,M) be a complete local ring, G Í SpecT such that G is nonempty and the number of maximal elements in G is finite. Then there exists a local domain A such that the completion of A is T and the generic formal fiber of A is exactly G if and only if T is a field (and G = {(0)}) or the following conditions hold: 1. M Ï G, and G contains all the associated primes of T 2. If Q Ï G and P Î SpecT such that P Í Q then P Î G 3. If Q Î G then Q Ç prime subring of T = (0)

From this theorem and its proof, we will also derive some more specific theorems, including a characterization of completions of excellent domains with semi-local generic formal fiber in the characteristic zero case.

On Completion and Tight Closure

Brian P. Katz

Tight closure is one of the most active areas in current algebra research. It is conjectured that tight closure and completion will commute for excellent rings, finally providing ring theorists with a sufficiently strong condition to study the relationship between a ring and its completion. I constructed two local rings, a unique factorization domain and an “almost excellent” domain (all fibers are geometrically regular except the generic one), for which tight closure and completion do not commute.

Phase Transitions of Multidimensional Generalizations of the Knauf Number-Theoretical Chain Model

Edvard Major

This thesis briefly reviews basic concepts of statistical mechanics. A detailed exposition of the Farey Number-Theoretical Chain (FNTC) model is provided. Critical phenomenon of this statistical-mechanic model is further discussed. The Knauf Number-Theoretical Chain (KNTC) model is revisited, and an elegant new proof of exact phase transition location is provided.

A couple of new two-dimensional number sequence models that assume Knauf-like, denominator interactions are proposed. The first one is based on a triangle sequence introduced by Von Rudolf Monkemeyer and D. Grabiner. The existence of the model’s phase transition is verified. To construct the remaining models, a couple of new continued fraction Re2 algorithm-generalizations are proposed, and their properties analyzed. The existence of respective phase transitions is proved.

Generalized Continued Fractions and the Units of Cubic Fields

Mark P. Rothlisberger

Every real number a has a continued fraction expansion which can be developed in several ways. We will examine some of the properties of continued fractions in order to work on generalizing them. Contained in Sections 1, and 3, this work is well known. An introduction to the Geometry of Numbers developed by Minkowski can be found in [4], while a slightly different, but still geometric approach to continued fractions is presented in [5]. Section 2 is also an introduction to well-known background material. Continued fractions are closely tied to distinguishing quadratic irrationals and determining properties of the algebraic fields that they determine. The generalized continued fractions we develop and investigate will follow the approach of Minkowski by using convex bodies in R3, namely parallelepipeds, to approximate certain vectors and planes. These methods will resemble the geometric development of continued fractions from Section 3, and we will demonstrate that some of the results from continued fractions generalize as a result of this method. Two approaches will be given: the first, contained in Section 4, is not original; the same approach is contained in [2] under the title A Criterion for Algebraic Numbers. The second generalization, in Section 5, is original in the choice of parallelepipeds, but employs methods from The Theory of Continued Fractions in [2]. We will also examine the connection between the two generalizations.

Augmentations of Knot and Link Complements

Eric M. Schoenfeld

It is conjectured that the meridian length for any alternating knot complement is bounded above by 2, though the best known upper bound approaches 3 for high crossing knots. We show that the bound of 2 is held for “almost all” alternating knots, and indeed almost all alternating links as well. Moreover, we show that any knot complement, and indeed any link complement, can be realized as Dehn surgery on a special type of link with meridian length exactly 2.

Singular Maps of Surfaces into Hyperbolic 3-Manifolds

Eric Michael Katerman

We construct singular maps of surfaces into hyperbolic 3-manifolds in order to find upper bounds for meridian length, longitude length, and maximal cusp volume of those manifolds. We also provide ample background and history of hyperbolic geometry and 3-manifold theory for this exposition to be accessible to undergraduate mathematics majors. Generalizations and attempts to strengthen our results are also included for completeness.

Spatially Explicit Biological Population Models

Jonathan A. Othmer

This thesis presents a spatially explicit hybrid system population model. Populations are assumed to exist in discrete patches, which we approximate using a hexagonal tiling of the plane. Dynamics within one patch are controlled by a system of differential equations while intra-patch dynamics are controlled via a set of transition functions and threshold values. We explore a variety of behaviors of this model, filling the plane, reaching static equilibrium, and reaching dynamic equilibrium. We also present and explore a spatially attracting, self-synchronizing cycle that arises out of the model.

On Solution to the Generalized Pell Equation with Applications to Diophantine Approximation

Charles Samuels

Suppose pn/qn are the convergents of c, where c is a positive integer not a perfect square. We show that NewtonÕs method applied to F(x) = x2 Ð c with initial approximation pmlÐ1/qmlÐ1, for any natural number m, generates the sequence {p2nmlÐ1/p2nmlÐ1}, n = 0,1,2,É. Subsequently, we generalize these results to all functions of the form F(x) = x2 Ð bx Ð c, where b > 0, c > 0 are integers such that b2 + 4c is not a perfect square. We finally explore the dynamics of some polynomial functions in the p-adic numbers.

Calculus: Its History, Teaching, and Pedagogy

Camille S. Burnett

There are three components to this study – the first, a historical and analytical survey of the calculus; the second, a comparison of teaching methods and approaches across two cultures, the United States and Jamaica; the third, a section on course module development. In the history of the calculus, we examine how calculus developed, the motivation of the theory and the major problems encountered. We present an overview of contributions by early mathematicians, a more in-depth look at the work of Newton and Leibniz, and discussed how calculus was made rigorous in the 1800s.

Rank One Mixing and Dynamical Sequences

Darren Creutz

Rank one transformations are a class of ergodic transformations constructed using a cutting and stacking method. We show that a class of rank one transformations characterized by adding spacer levels that have restricted growth but also tending toward a uniform type of distribution are indeed mixing transformations. All previously known mixing rank one transformations, including staircase transformations satisfying the restricted growth condition, fall into our class.

Four-Manifolds and Related Topological Investigations

Richard Haynes

In this thesis I investigate high dimensional manifolds through the lens of four-dimensional topology. In this vein, I use invariants of four-dimensional spaces to specify related properties of larger ambient spaces. This relationship provides restrictions on the possible structures of these larger spaces.

Power Weak Mixing and Recurrence in Infinite Measure

Abhaya N. Menon

In this thesis, we explore the idea of Power Weak Mixing and demonstrate the existence of a family of transformations exhibiting this property. We then investigate the recurrence properties of this family of transformations.

An Improvement on Legendre’s Theorem from Diophantine Approximation

Rungporn Roengpitya

In this thesis, we explore two questions from Diophantine analysis. First, we improve Legendre’s Theorem by finding the best possible constants for j, the golden ratio, and the generalized golden ratio j2 and j3. Then, we explore the nature of the function ;x;where x is an irrational number in one and two dimensions.

Uniqueness in mimensional Triangle Sequences

Tegan Cheslack-Postava

In the generalization of continued fractions introduced by Garrity, each point in an m-dimensional simplex is represented by a sequence of nonnegative integers. After introducing the algorithm for generating these sequences, we show that the representation map is in general not injective. We use the notions of partition simplices and associated dimension to investigate the set of points identified by an m-triangle sequence.

Strict Minimality of Alternating Knots in S x I

Thomas Fleming

In the late 1800’s Tait conjectured that for knots that lie in the plane, a reduced alternating projection has the smallest possible number of crossings for any projection of that knot, and that any non-alternating projection must have more crossings. This fact was proven in 1984 by Kaufmann, Murasugi, and Thistlethwaite. In the summer of 1999, the Colin Adams directed Knot Theory SMALL group of Fleming, Levin and Turner was able to prove that if the knot projection lies on a surface (such as a torus) and the knot lies in a layer around that surface (the surface cross an interval), then a reduced alternating projection has the smallest possible number of crossings for any projection of that knot. We will extend this work to prove that for a knot in a surface cross an interval, a reduced alternating projection of the knot must have strictly fewer crossings than a non-alternating projection. We will use arguments based on a generalized Kauffman bracket polynomial, Menasco-type geometric arguments, and covering space techniques.

Applying a Bayesian Hierarchical Model to a Data Set Consisting of Hospital Mortality Rates

Cory Heilmann

Bayesian hierarchical modeling is often applicable to data sets where the data originate from many different entities, each of which measures a similar quantity. Examples of these data sets are students’ test scores from different schools and mortality rates from different hospitals. This sort of modeling is particularly useful when we wish to estimate means and variances of each entity, but some of the entities have low numbers of observations, and thus the maximum likelihood estimator is unreliable. This thesis uses a Bayesian hierarchical model on a data set consisting of the mortality rates from organ transplants in 131 hospitals. We will rank the hospitals according to their predicted mortality rate, and also decide whether the mortality rates of small hospitals appear to be larger than the mortality rates of large hospitals.

A Structural Analysis of the Triangle Iteration

Adam Schuyler

Classically, it is know that the continued fraction sequence for a real number a is eventually periodic if and only if a is a quadratic irrational. In response to this, Hermite posed the general question which asks for ways of representing numbers that reflect special algebraic properties. Specifically, he was inquiring about possible generalizations of the continued fraction. In this paper we will study the triangle iteration, a two-dimensional analogue of the continued fraction. We will take a primarily geometric approach and look at the probabilities of the occurrences of certain sequences.

Relationships and Syzygies in Classical Invariant Theory for Vector-Valued Bilinear Forms

Zachary J. Grossman

The goal of invariant theory is to describe the algebra of invariants for a vector space under a given group action. After introducing invariant theory and its two main problems, we will prove the Second Fundamental Theorem for vector-valued bilinear forms, which describes the basis relations between invariants of vector-valued bilinear forms.

Bend Minimization for Hexagonal Graph Drawing

Davina Kunvipusilkul

In this thesis, we give an overview of some of the optimization problems that arise in computing orthogonal and hexagonal drawings of graphs. We then employ the concepts of spine and spirality to develop a polynomial-time algorithm that, given a biconnected, 6-planar, series parallel graph, computes a hexagonal drawing having the minimum number of bends over all possible embeddings. The algorithm runs in O(n^8) time. This work extends similar results by Di Battista, Liotta, and Vargiu on bend minimization for orthogonal graph drawings.

Supercrossing Number of Knots

One of the oldest invariants utilized for the study of knots is the crossing number of a knot, which is the least number of crossings in any projection of the knot. In this thesis, the supercrossing number of knots, a variation on crossing number, is investigated. It is proved that the supercrossing number is always at least 3 greater than the crossing number. The trefoil knot is shown to have supercrossing number 6 or 7. The crossing map is then investigated as a tool to understand the supercrossing number.

The Cusped Hyperbolic Three-Manifolds of 2nd Smallest Volume

Scott B. Reynolds

A hyperbolic 3-manifold is defined as the quotient of hyperbolic 3-space by a discrete group of fixed point-free isometries. It is known that the set of volumes of all noncompact (cusped) hyperbolic 3-manifolds is well-ordered, and in 1987, Professor Adams proved that the hyperbolic manifold of smallest volume (V=1.0149…) is the Gieseking manifold. Working in the upper-half space model of hyperbolic 3-space, the Gieseking manifold is obtained by taking a regular ideal (vertices at infinity) tetrahedron and identifying its edges with each other. This paper provides background on these types of problems and then proves that, for a large class of cusped hyperbolic 3-manifolds, the manifold of second-smallest volume is the non-orientable one obtained by gluing two 45-45-90 (angles between vertical faces, measured in degrees) ideal tetrahedra together. This manifold has volume approximately equal to 1.83.

Generic Formal Fibers of Excellent Local Polynomial Rings

Aaron D. Weinberg

Let (T, M) be a complete regular local ring of dimension at least two containing the rationals, such that the cardinality of the residue field T/M is at least the cardinality of the real numbers. Suppose p is a nonmaximal prime ideal of T and L is a set of prime ideals of T[[X 1 , …, X n ]] (where X 1 , …, X n are indeterminates) such that the cardinality of L is strictly less than the cardinality of T/M, Q intersected with T is a subset of p for each Q in L, and if Pi is the prime subring of T, then Pi[X 1 , …, X n ] intersected with Q is the zero ideal for each Q in L. Then there exists an excellent regular local ring A such that the completion of A is T, the generic formal fiber of A is local (this means that the ring T \otimes_A K is a local ring where K is the quotient field of A) with p \otimes_A K its maximal ideal, and Q intersected with A[X 1 , …, X n ] is the zero ideal for each Q in L.

On Spheres and Smooth Structures of Four-Dimensional Manifolds

Craig C. Westerland

For smooth four-dimensional manifolds M we explore the representation of classes in H2(M) as smooth embeddings of two-spheres into M. For simply connected manifolds, it is known that such a representation is always possible for continuous embeddings, but the smooth case is in general mostly unknown. Given a class that can be represented in this manner, we determine several bounds on the self-intersection of the class. Additionally, we demonstrate a relationship between the occurrence of certain types of these homology classes that can be represented as smooth spheres in a manifold and the smooth structure on that manifold. Finally, we present an abortive attempt to determine a class of manifolds whose second homology contains no non-characteristic classes that are representable as smooth spheres. To introduce the appropriate background to complete the work herein, we also include several chapters on differential topology, algebraic topology, and four-manifold theory.

Smooth 2-Spheres in Some Compact, Orientable, Simply Connected 4-Manifolds

Alexandre Wolfe

This thesis discusses techniques and results in the study of necessary conditions for representability of second homology classes of compact, orientable, simply connected 4-manifolds by smooth 2-spheres.

Comparison of Ordinary Differential Equation Models of HIV Infection

Laura Louise Christensen

Many ordinary differential equation models have been bused in research on HIV to te et al and Hraba et al) are compared with and without treatment incorporated. The conclusions of this comparison are as follows. The McLean model, which is very similar to the Perelson model, but designed to model dynamics during treatment, is robust only for initial conditions which reflect an infected steady-state and not for infection dynamics from initial inflection or after the completion of a treatment course. Treatment dynamics are compared between the Perelson and McLean models. Particular treatments were implemented on both the Hraba and Perelson models yielding the conclusion that, though the models are quite different, they give similar predictions of relative treatment effectiveness.

Cost Minimizing Networks Separating Immiscible Fluids in R 2

Brian Elieson

Cost minimizing networks model certain behavior of immiscible fluids in the plane. This paper proves the existences of minimizers of straight lines with an upper bound on the number of nodes, closely following the work of Alfaro. It provides some basic examples of minimizers. The paper also gives sufficient conditions for an upper bound on the number of regions meeting around a point.

Characterization of Completions of Integral Domains

Deborah L. Greilsheimer

Christer Lech characterized the complete local (Noetherian) rings that are completions of domains. We reprove Lech’s result showing that a complete local ring T is the completion of a local domain if and only if no integer of T is a zero divisor, and, unless equal to (0), the maximal ideal of T does not belong to (0) as an associate prime ideal. Moreover, suppose p (does not equal) M is a prime ideal of T such that Q is an associated prime of T implies Q à p, and suppose that |{q Î Spec T | q Ë p}| £ | T/M 2 | and p intersected with the prime subring of T is the zero ideal. In this case, we construct a local domain A such that  = T and the generic formal fiber ring of A is local with p * A K the maximal ideal where K is the quotient field of A.

Weak Mixing, III0 Staircase Zd Actions

Erich Muehlegger

This thesis presents two new examples of staircase Z d actions, functions mapping points from Z d x R to R. Expanding on the work of Silva/Adams and Touloumtzis, the first construction is shown to be an infinite measure preserving action with weakly mixing basis transformations. The second and more interesting example is a type III 0 action with weakly mixing basis transformations. In addition, the several concepts and criteria applying to Z 2 actions are generalized to their Z d counterpart.

Bayesian Prediction Intervals for Symmetric Shrinking Linear Smoothers

Jason Ross Schweinsberg

In many statistical problems, it is important to estimate the relationship between a dependent variable y and some independent variables, so that given values for the independent variables, a 95 percent prediction interval for y can be computed. Here we describe how Bayesian methods can be used to calculate prediction intervals for a class of modeling methods called symmetric shrinking linear smoothers. We show that how well these “Bayesian prediction intervals” perform can be related to simple properties of the smoother. When one “smoothing parameter” is chosen optimally, we show that Bayesian prediction intervals perform well asymptotically for generalized ridge regression. For other smoothers, the asymptotic performance of Bayesian prediction intervals is conjectured to depend on the eigenvalues of a linear operator called the covariance operator.

Outer-crossing Numbers: A New Parameter for Graphs

Alexander Woo

Outer-crossing numbers of graphs are defined and basic properties are given. The outer-crossing numbers of complete bipartite graphs are found. Some conjectures and a generalization to surfaces other than the plane are discussed.

Finding Incompressible Surfaces

Jeffrey Bevelander

In an attempt to supplement the machinery already developed to identify knots and links, this thesis presents an algorithm which will detect the presence of incompressible surfaces, which can assist in the process of knot and link identification and analysis. Examining the link in its ideal triangulated form, the algorithm produces the simpler surfaces that can be expressed “nicely” by interconnecting triangles and quadrilaterals. Expressing a surface “nicely” basically means that each triangle and each quadrilateral used in the representation lies entirely in a single tetrahedron, and that none of the polygons intersect each other in a given tetrahedron. These two restrictions create a combinatorial requirement for a surface that sits “nicely” in the tetrahedra. Utilization of this requirement allows for the identification of the sets of triangles and quadrilaterals that lie “nicely” within the tetrahedra, and upon associating these sets of polygons with the surfaces they form, it is then possible to identify the surfaces that can be placed “nicely” into a link’s ideal triangulated form. Since, incompressible surfaces always have a “nice” representation in the ideal triangulation, once we have identified our “nice” surfaces, we will have found all the simple incompressible surfaces in a knot complement, and gathered information that will further our efforts towards identifying the knot or link.

Analysis of Manifolds Using Morse-Smale Homology

David DelaCruz

A topological object can be defined as a set of points in a space. A particularly beautiful topological object to examine is the manifold.

Given two n -manifolds, it is interesting to know if they are topologically equivalent — that is, whether we can bend, twist, and stretch one to get the other. The topological invariants of two manifolds must be the same if two manifolds are the same under topology, one such invariant is homology groups.

Singular homology theory describes homology groups for manifolds in the abstract. Morse-Smale homology allows us to capture homology groups algebraically as well.

The thesis is an exposition of singular homology theory, Morse theory, and Morse-Smale homology, followed by an algorithm that can be used to approximate Morse Smale gradient flows on algebraically-defined manifolds.

Computing the Intersection Homology Groups of a Complex Algebraic Variety

Christopher French

An algorithm is given to compute the intersection homology groups for a complex algebraic variety. Two previously developed algorithms, the Collin’s cad algorithm and Prill’s Adjacency algorithm, are presented and used.

One Approach to Factoring Multivariate Rational Polynomials Over the Complex Numbers

Dimitry Korsunsky

Factoring a given multivariate polynomial is an important task in symbolic computation. Potential uses for an efficient solution to this problem could be found in various branches of applied mathematics, such as computer-aided design and theorem proving. Several algorithms giving different methods for factoring multivariate polynomials had been created over the years (Noether 1922, Davenport and Trager 1981, Christov and Grigoryev 1983 etc.). The theoretical basis for the algorithm, implementation of which is the subject of this paper had been put forward in Bajaj et al [4]. There it is proved that the suggested approach when implemented in parallel will execute in shorter time as compared to earlier solutions. Although a sequential solution which was implemented achieves lower efficiency there is a significant advantage in that it can be used in a large variety of settings. The program had been written using the Mathematica software package.

Bumper Drawings: A New Type of Proximity Drawing

Michael Pelsmajer

Open and closed ß-bumper drawings are defined exactly as ß-drawings, except that proximity regions contain no vertices and edges. Open and closed [[infinity]]-bumper graphs are completely classified. Maximal outerplanar drawings are defined for 1-bumper drawings, and partial results and methods are detailed.

Hyperbolic 3-Orbifolds

Edward Welsh

Suppose we have a hyperbolic 3-orbifold with discrete fundamental group G generated by two elliptic transformations, alpha and beta. This thesis finds restrictions on the possible distances between the axes of alpha and beta under various conditions. Introductions to both hyperbolic geometry and algebraic topology are included.