DSNT Seminar: Random walks on groups and amenability dichotomies
- Date: 28 May 2025, 10:15–11:00
- Location: Ångström Laboratory, 90104
- Type: Seminar
- Lecturer: Richard Sharp (University of Warwick)
- Organiser: Matematiska institutionen
- Contact person: Reza Mohammadour
Please note the unusual day, time, and room. Richard Sharp (University of Warwick) gives this seminar. Welcome to join!
Abstract: A famous "amenability dichotomy" result of Kesten from 1959 relates symmetric random walks on countable groups to amenability. Precisely, provided the support of the walk generates the group, the probability of return to the identity in n steps decays exponentially fast if and only if the group is not amenable. I will present a version of the dichotomy for non-symmetric walks. Time permitting, I will also discuss a new ratio limit theorem for amenable groups. This is joint work with Rhiannon Dougall.
This is a seminar in our seminar series on Dynamical Systems and Number Theory (DSNT).