# Math Calendar

### Upcoming Events

## Undergraduate Seminar

## Probabilistic Methods in Combinatorics

Bogdan Chornomaz, Vanderbilt University

Location: Stevenson 1206

Typically, probability theory deals with things which are uncertain on the very ground level. Of course, to struggle with uncertainty is harder, but what can we do? How much simpler would things be if only our objects and actions were clearly determined. Or would they? Surprisingly, it turns out that if our objects are by no means indeterminate, but still complicated enough, it might be convenient to study them as if they were probabilistic. Think of it as saying “whatever” at some point in an argument, but in a strictly mathematical way. In this talk, we will consider some simple examples where these methods can be fruitfully applied.

## Graduate Student Tea

## Graduate Student Tea

Location: Stevenson 1425

## Topology & Group Theory Seminar

## Hierarchically Hyperbolic Groups: An Introduction

Jason Behrstock, CUNY

Location: Stevenson 1308

Hierarchically hyperbolic spaces provide a uniform framework for working with many important examples, including mapping class groups, right angled Artin groups, Teichmuller space, most cubulated groups, and others. In this talk I’ll provide an introduction to studying groups and spaces from this point of view, both describing new tools to use to study these groups and applications of those results. This talk will include joint work with Mark Hagen and Alessandro Sisto.

## Number Theory Seminar

## Talk Title TBA

Doug Hardin, Vanderbilt University

Location: Stevenson 1320

## Subfactor Seminar

## Connes Fusion on the Unit Circle

Bin Gui, Rutgers University

Location: Stevenson 1432

In subfactor theory, one can construct C*-tensor categories using either Connes fusions (Connes relative tensor products) of bimodules or compositions of endomorphisms of factors. It is well known that these two approaches are more or less equivalent. In algebraic conformal field theory (conformal nets), the latter approach leads to the Doplicher-Haag-Roberts (DHR) superselection theory, from which one can construct braided C*-tensor categories for the representations of conformal nets. In this talk, I will explain how to construct braided C*-tensor categories using Connes fusions. If time permits I will explain how this approach leads to the notion of categorical extensions of conformal nets.

## Computational Analysis Seminar

## Error Bounds in Fourier Extension Approximations

Karl Liechty, DePaul University

Location: Stevenson 1320

A truncated Fourier series is a very effective way to approximate smooth periodic functions, but if a function defined on an interval is not periodic, its nearest truncated Fourier series is not a good approximation near the endpoints of the interval due to the Gibbs phenomenon. One method to deal with this issue, known as Fourier extension or Fourier continuation, is to extend the function smoothly to one which is periodic on a slightly larger interval, and approximate by truncated Fourier series with a slightly larger period. I will discuss asymptotic error bounds for these truncated Fourier series as the number of Fourier modes becomes large. In particular I will discuss the issue of obtaining uniform bounds from a discrete L^2 construction. This is joint work with Jeff Geronimo.

## PDE Seminar

## Talk Title TBA

Theodore Drivas, Princeton University

Location: Stevenson 1307

## Topology & Group Theory Seminar

## Talk Title TBA

Genevieve Walsh, Tufts University

Location: Stevenson 1308

## Topology & Group Theory Seminar

## Talk Title TBA

Talia Fernós, University of North Carolina, Greensboro

Location: Stevenson 1308

## Number Theory Seminar

## Talk Title TBA

John Voight, Dartmouth College

Location: Stevenson 1320

## Topology & Group Theory Seminar

## Talk Title TBA

Michael Ben-Zvi, Tufts University

Location: Stevenson 1308

## PDE Seminar

## Talk Title TBA

Geng Chen, University of Kansas

Location: Stevenson 1307

## Topology & Group Theory Seminar

## Talk Title TBA

Carolyn Abbott, Columbia University

Location: Stevenson 1308

## Number Theory Seminar

## Talk Title TBA

Marie Jameson, University of Tennessee

Location: Stevenson 1320

## Topology & Group Theory Seminar

## Talk Title TBA

Michael Hull, University of North Carolina, Greensboro

Location: Stevenson 1308