## Seminars and Colloquia by Series

### TBA by Tom Kelly

Series
School of Mathematics Colloquium
Time
Thursday, May 6, 2021 - 11:00 for 1 hour (actually 50 minutes)
Location
https://us02web.zoom.us/j/87011170680?pwd=ektPOWtkN1U0TW5ETFcrVDNTL1V1QT09
Speaker
Tom KellyUniversity of Birmingham

TBA

### TBA by Po-Ling Loh

Series
School of Mathematics Colloquium
Time
Thursday, April 22, 2021 - 12:00 for 1 hour (actually 50 minutes)
Location
Zoom
Speaker
Po-Ling LohUniversity of Cambridge

Please Note: Note the unusual time: 12:00pm.

TBA

### TBA by Rob Morris

Series
School of Mathematics Colloquium
Time
Thursday, April 8, 2021 - 11:00 for 1 hour (actually 50 minutes)
Location
https://us02web.zoom.us/j/87011170680?pwd=ektPOWtkN1U0TW5ETFcrVDNTL1V1QT09
Speaker
Rob MorrisNational Institute for Pure and Applied Mathematics, Rio de Janeiro, Brazil

TBA

### TBA by Yao Yao

Series
School of Mathematics Colloquium
Time
Thursday, April 1, 2021 - 11:00 for 1 hour (actually 50 minutes)
Location
https://us02web.zoom.us/j/87011170680?pwd=ektPOWtkN1U0TW5ETFcrVDNTL1V1QT09
Speaker
Yao YaoGeorgia Institute of Technology

TBA

### TBA by Jinchao Xu

Series
School of Mathematics Colloquium
Time
Thursday, March 18, 2021 - 11:00 for 1 hour (actually 50 minutes)
Location
Zoom
Speaker
Jinchao XuPennsylvania State University

TBA

### Impossibility results in ergodic theory and smooth dynamical systems

Series
School of Mathematics Colloquium
Time
Thursday, February 25, 2021 - 11:00 for 1 hour (actually 50 minutes)
Location
https://us02web.zoom.us/j/87011170680?pwd=ektPOWtkN1U0TW5ETFcrVDNTL1V1QT09
Speaker
Matthew ForemanUniversity of California, Irvine

The talk considers the equivalence relations of topological conjugacy and measure isomorphism on diffeomorphisms of compact manifolds of small dimension. It is shown that neither is a Borel equivalence relation.  As a consequence, there is no inherently countable method that,  for general diffeomorphisms $S$ and $T$, determines whether $S\sim T$. It is also shown that the Time Forward/Time Backward problem for diffeomorphisms of the 2-torus  encodes most mathematical questions, such as the Riemann Hypothesis.

This work is joint with B Weiss and A Gorodetski.

### Mathematical modeling of the COVID-19 pandemic: an outsider's perspective

Series
School of Mathematics Colloquium
Time
Thursday, February 18, 2021 - 11:00 for 1 hour (actually 50 minutes)
Location
https://us02web.zoom.us/j/87011170680?pwd=ektPOWtkN1U0TW5ETFcrVDNTL1V1QT09
Speaker
Wesley PegdenCarnegie Mellon University

In this talk we will discuss epidemic modeling in the context of COVID-19.  We will review the basics of classical epidemic models, and present joint work with Maria Chikina on the use of age-targeted strategies in the context of a COVID-19-like epidemic.  We will also discuss the broader roles epidemic modeling has played over the past year, and the limitations it as presented as a primary lens through which to understand the pandemic.