Past Events

What do thunderstorms look like on the inside? Were they any different 30 to 50 thousand years ago? How might they change in the next 100 years as global temperatures continue to rise? The presentation will start with how a thunderstorm looks in 3-D...

Convective storms are highly intermittent and intense, making their occurrence and strength difficult to predict. This is especially true for climate models, which have grid resolutions much coarser (e.g., 100 km) than the scale of a storm’s...

Monitoring marked individuals is a common strategy in studies of wild animals (referred to as mark-recapture or capture-recapture experiments) and hard to track human populations (referred to as multi-list methods or multiple-systems estimation). A...

We survey questions, conjectures and results, old and new, about the distribution of prime numbers. We concentrate on the existence and distribution of primes in the integer value sets of polynomials having integer coefficients. The talk is directed...

Abstract: Often, interesting knotting vanishes when allowed one extra dimension, e.g. knotted circles in 3-space all become isotopic when included into 4-space. Hughes, Kim and I recently found a new counterexample to this principle: for g>1, there...

Estimating the COVID-19 infection fatality rate (IFR) has proven to be challenging, since data on deaths and data on the number of infections are subject to various biases. I will describe some joint work with Harlan Campbell and others on both...

Paley graphs connect many branches of mathematics, notably combinatorics and number theory. Inspired by the Erdős-Ko-Rado (EKR) theorem for Paley graphs of square order (first proved by Blokhuis) and recent development of the study of EKR-type...

The theme of this lecture is the dichotomy between amenability and non-amenability, both in operator algebras and ergodic theory. I will review the fundamental classification results for amenable von Neumann algebras due to Connes and Haagerup. Then...

Khovanov homology, though relatively young, is difficult to survey in an hour. This talk will nevertheless attempt to do so, by focussing on the problem of characterizing thin links—those links with simplest-possible Khovanov homology. This is a...

Diffusion methods help understand and denoise data sets; when there is additional structure (as is often the case), one can use (and get additional benefit from) a fiber bundle model.