2 papers
math.DS2025
Kac's Lemma and countable generators for actions of countable groups
Tom Meyerovitch, Benjamin Weiss
Kac's lemma determines the expected return time to a set of positive measure under iterations of an ergodic probability preserving transformations. We introduce the notion of an \e…
math.DS2025
The isomorphism problem for group actions
Matthew Foreman, Benjamin Weiss
We discuss the isomorphism problem for ergodic actions of locally compact groups. In particular we show that the conjugacy relation is not Borel for ergodic measure preserving acti…