# 2014-2015 Seminars and Colloquia

## department of mathematics

### Boston College Distinguished Lecturer in Mathematics Series

**Jordan Ellenberg, Vilas Distinguished Achievement Professor in Mathematics**, University of Wisconsin will be the Distinguished Lecturer in our annual lecture series. Prof. Ellenberg will give three lectures on February 16-18, 2015

**Monday, February 16th at 4:30 pm in McGuinn 121 "How to get rich playing the Massachusetts Lottery"**

Abstract: From 2005 to 2012, a group of friends who met as MIT undergraduates won over 3 million dollars playing a poorly designed game in the Massachusetts lottery. How did they do it, and how did they get away with it? Their strategy, it turns out, involved the theory of combinatorial designs. I’ll explain what combinatorial designs are, what they have to do with lotteries, their relation with geometry over finite fields, and the 2014 breakthrough of Peter Keevash that solved one of the major open problems in the subject.

**Tuesday, February 17th at 5:00 pm in Gasson 305 "Arithmetic statistics over function fields, or: the topology of numbers"**

Abstract: The talk will introduce the fruitful analogy between number fields like Q and function fields over finite fields, like F_q(t). We will concentrate especially on the asymptotics of enumerative questions coming from number theory, a subject often known as “arithmetic statistics.” It turns out that when you ask arithmetic statistics questions over F_q(t), an unexpected relation to algebraic topology emerges. We will explain, for instance, why the questions “how many squarefree integers are there between N and 2N” and “how many primes are there between N and 2N” transform into a question about the cohomology of Artin’s braid group, and why “1-1/q” is the algebraic geometer’s version of “6/pi^2.” I’ll also talk about a deeper example, connecting the Cohen-Lenstra conjectures about average behavior of class groups of number fields with the cohomology of moduli spaces of curves called Hurwitz spaces; in particular, we will explain how topological theorems about stable cohomology of mapping spaces provide the only known proofs of statements of Cohen-Lenstra type over function fields. (Joint work with Akshay Venkatesh and Craig Westerland, and with Tom Church and Benson Farb.)

**Wednesday, February 18th at 3:00 pm in Gasson 305 "Arithmetic statistics over function fields, II: recent developments"**

Abstract: In this talk, I’ll talk about recent developments stemming from the theme of the first talk, arguing that almost every interesting question in arithmetic statistics is connected to an interesting question in geometry when transposed to the function field setting. In particular, the topological viewpoint provides a kind of machine for generating geometrically motivated (and hopefully correct!) conjectures, giving a coherent common grounding for many popular conjectures in arithmetic statistics, while suggesting many others that haven’t yet been seriously investigated. In the rare contexts when the geometrically motivated conjecture conflicts with an existing conjecture, the geometrically motivated conjecture seems to win.

### BC-MIT Number Theory Seminar

Organizers: Ben Howard and David Geraghty at BC, and Bjorn Poonen at MIT.

### BC Math Society/Mathematics Department Undergraduate Lectures

**Wednesday, March 19, 2014 - Stokes S209**

Title: The Framingham Heart Study and the Development of Cardiovascular Disease Risk Prediction Functions

Abstract: The Framingham Heart Study (FHS) began in 1948, under the direction of National Heart Institute (now the National Heart Lung and Blood Institute), with the objective of assessing risk factors that contribute to cardiovascular disease (CVD) by examining and following a large cohort of participants from Framingham, MA (n=5,209) who did not have CVD or overt symptoms of CVD. The participants have been periodically examined and followed through death, with approximately 100 of these original cohort participants still alive today. Since 1971, the original cohort’s adult children and their spouses, and since 2002, the grandchildren of the original cohort, have been examined and followed. Also, since 1994, participants reflecting a more diverse Framingham community have been examined and followed. Overall, FHS involves approximately 15,000 participants. The abundance of risk factor and follow-up data collected over the years has allowed FHS to be among the leaders in CVD risk prediction, both clinically and methodologically. Here, we will provide a brief history of FHS, discuss clinical and methodological development of CVD risk prediction, provide examples of how FHS risk prediction models are used by physicians today, and briefly discuss current research.

### BC Geometry/Topology Seminar

Meets Thursdays at 4:00 pm in Carney 309

Schedule: https://www2.bc.edu/ian-p-biringer/seminar.html

### BC Colloquium Series

To be determined.

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### Boston Area Links

The Mathematical Gazette is published weekly by the Worcester Polytechnic Institute Mathematical Sciences Department. It provides a list of mathematical seminars and colloquia in the Massachusetts area.

### BC Number Theory/Algebraic Geometry Seminar

##### BC Number Theory and Algebraic-Geometry Seminar

Meets Thursdays at 3:00 p.m. in Carney 309

Schedule: https://www2.bc.edu/dubi-kelmer/NTAGseminar/NTseminar.html

##### BC Math Society Undergraduate Lecture Series

September 24, 2014, 3:00 p.m., Prof. Bill Keane (BC)

Title: Eureka! The Life and (Some of the) Work of Archimedes.