Colloquium: Fall 2025

Time & Location:  All talks will be in Gibson Hall 126-A on Thursdays at 3:30 pm unless otherwise noted.  In order to have time to talk informally with the speakers, we will schedule a time we call “Tea with the speaker” that everyone is welcome to join.

Organizer: Tommaso Buvoli and SamuelPunshon-Smith

 

Thursday, September 25

Colloquium

Topic: Riding the neural waves: Mathematics of nonlocally coupled waves in active media

Speaker: Bard Ermentrout - University of Pittsburgh (Host: Lisa Fauci)

Abstract:  Recent improvements in technology have enabled neuroscientists to simultaneously record activity of many neurons at high spatial and temporal resolution. This has allowed them to discover that activity is organized into a variety of spatial patterns such as plane waves, bullseyes, and rotating waves.  In this talk, I want to distinguish two different classes or wave-like activity: (1) evoked waves or "trigger waves", and (2) phase waves.  In the former, the onset of activity in one area requires prior activity in a  neighboring area, while in the latter, the apparent wave motion is a consequence of timing differences between areas.  I will present some recent results on the role of inhibition in controlling the propagation and stability of trigger waves. Next, I will consider coupled phase equations that describe spatio-temporal activity in intrinsically oscillatory media.  I will describe recent work where we are able to extract hidden waves from human cortical recordings. Finally, I will present some work showing how ongoing phase waves  can promote the propagation of trigger waves in an anisotropic manner.

Location: Gibson Hall 126-A
Time: 3:30 pm

 

Thursday, October 16

Colloquium

Topic: What are solitons?

Speaker: Deniz Bilman  - Affiliation: University of Cincinnati (Host): Ken McLaughlin

Abstract:  This is an introductory talk on the story of mathematical research on waves, aimed at graduate students from all areas and undergraduate students. This will serve as both a colloquium talk and a precursor to a self-contained mini course that will be given by the speaker in our “Integrability and Beyond!!!” Seminar, starting on October 20.  

Location: Gibson Hall 126-A
Time: 3:30 pm

 

Thursday, October 23

Colloquium

Topic: A summation formula for Hurwitz class numbers

Speaker: Kalani Thalagoda - Tulane University

Abstract:  The Hurwitz class numbers, $H(n)$, count SL$_2(\mathbb{Z})$-classes of binary quadratic forms inversely weighted by stabilizer size. They are famously connected to the sum of three squares problem and to class numbers of imaginary quadratic fields. The work of Zagier in 1975 showed that their generating functions are related to a weight $3/2$ Harmonic Maass form. In this talk, I will discuss a summation formula we obtained for the Hurwitz class numbers generating function. This is joint work with Olivia Beckwith, Nicholas Diamantis, Rajat Gupta, and Larry Rolen  

Location: Gibson Hall 414
Time: 3:30 pm

 

Thursday, October 30

Colloquium

Topic: TBA

Speaker: Fedya Manin - University of Toronto (Host: Rafal Komendarczyk)

Abstract:  TBA 

Location: Gibson Hall 126-A
Time: 3:30 pm

 

Thursday, November 13

Colloquium

Topic: TBA

Speaker: Anton Leykin  -  Affiliation Georgia Tech (Host: Kalina Mincheva and  Daniel Bernstein)

Abstract:  TBA 

Location: Gibson Hall 126-A
Time: 3:30 pm