Amitsur Seminar: Michael Chapman (HUJI)

Thu, 27/01/202211:00-12:00

Speaker: Michael Chapman (HUJI)
Title: Cutoff: new results and new methods.
Abstract:  In recent years, random walks on simplicial complexes proved extremely useful. They were used, for example, to uniformly sample matroid bases, and to define high dimensional analogues of expansion. Meanwhile, the cutoff phenomenon for random walks received lots of attention as well. A random walk exhibits the cutoff phenomenon if the transition from being far from mixed to being very mixed happens (relatively) abruptly. 
In this talk we plan to: 
  • Survey cutoff results and proof methods for graphs and for quotients of Bruhat-Tits buildings.
  • Discuss generalizations of a recent entropic approach due to Ozawa. 
  • Apply these generalizations to Ramanujan complexes that were not known previously to exhibit cutoff. 
  • Deduce cutoff results on Cayley graphs arising from high dimensional theory.

This talk is based on a joint work with Ori Parzanchevski and Yuval Peled.

ZOOM details:
Meeting ID: 828 1376 6376
Passcode: 649336