Groups & Dynamics Seminar: Ori Parzanchevski (HUJI)

Date: 
Thu, 22/05/202510:00-11:00
Location: 
Ross 70
Groups and dynamics seminar

Time: Thursday, May 22, 10:00
Place: Ross 70

Speaker: Ori Parzanchevski (HUJI)


 Title: Sharp cutoff for walks on graphs and groups

Abstract:


In the `80 Diaconis and others have observed that some naturally occuring Markov chains exhibit a cutoff phenomenon: in a short window, the distance from the stationary distribution drops from almost maximal to almost zero. It is conjectured that all transitive expander graphs exhibit this phenomenon, but so far very few examples are known. I will survey and explain some results on cutoff for walks on Ramanujan graphs and complexes, and their relation to expansion in groups.