Time : 2021/10/20 Wed 16:00~17:00

Location : Online (ZOOM) https://us02web.zoom.us/j/7720100585?pwd=UWJjK09YdUJEbjJPNXR6UlJSZ3RnZz09

Speaker : Ryu, Sieye (University of Sao Paulo)

 

Title : Predictability and Entropy for Actions of Amenable Groups 

 

Abstract: In this talk, we consider the following question due to Michael Hochman:

Suppose that a countable amenable group $G$ acts on a compact metric space $X$ and that $S \subset G$ is a semigroup not containing the identity of $G$. If every continuous function $f$ on $X$ is contained in the closed algebra generated by $\{sf : s \in S\}$, then does the action have zero topological entropy?

To provide an affirmative answer, we introduce the notion of an invariant random order. This is a joint work with Andrei Alpeev and Tom Meyerovitch.​