Seminars and Colloquia by Series

Surfaces and their Symmetries

Series
Undergraduate Seminar
Time
Monday, November 18, 2019 - 15:00 for 1 hour (actually 50 minutes)
Location
Skiles 171
Speaker
Justin LanierGeorgia Tech

Surfaces are some of the most basic examples of spaces. Although topologists have studied surfaces for a long time, they continue to fascinate. I'll give an overview of the study of surfaces over the past 150 years by highlighting work of seven mathematicians. We'll discuss the classification of surfaces, and we'll also discuss mapping class groups, which are collections of symmetries of surfaces. I'll also give the flavor of four of my own research projects about surfaces, one for each of four broad mathematical areas: group theory, geometry, topology, and dynamics.

TBA

Series
CDSNS Colloquium
Time
Monday, November 18, 2019 - 11:15 for 1 hour (actually 50 minutes)
Location
Skyles 005
Speaker
van.cyr@bucknell.eduBucknell University

Zero-free regions and central limit theorems

Series
Stochastics Seminar
Time
Thursday, November 14, 2019 - 15:05 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Marcus MichelenUniversity of Illinois, Chicago

Let X be a random variable taking values in {0,...,n} and f(z) be its probability generating function.  Pemantle conjectured that if the variance of X is large and f has no roots close to 1 in the complex plane, then X must be approximately normal. We will discuss a complete resolution of this conjecture in a strong quantitative form, thereby giving the best possible version of a result of Lebowitz, Pittel, Ruelle and Speer. Additionally, if f has no roots with small argument, then X must be approximately normal, again in a sharp quantitative form. These results also imply a multivariate central limit theorem that answers a conjecture and completes a program of Ghosh, Liggett and Pemantle.  This talk is based on joint work with Julian Sahasrabudhe.

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