Slow entropy-type invariants for group actions

01.11.2022 10:30

I will present a brief survey of recent developments in the theory of scaling entropy -- an invariant of a p.m.p. action of a countable group proposed by A. Vershik in the early 00-s.
Unlike the classical approach, we fix a measure space and vary a measurable metric focusing on its dynamics. The asymptotics of its epsilon net turns out to be an efficient invariant of p.m.p. actions with zero Kolmogorov-Sinai entropy.

We will discuss generic properties of this invariant, their connections to group properties, and how they help to answer Weiss' question about the existence of a universal zero-entropy system for amenable groups.

Lieu

Bâtiment: Conseil Général 7-9

Room 1-05,Séminaire Groupe et géométrie

entrée libre