English

Entropy, products, and bounded orbit equivalence

Dynamical Systems 2022-02-23 v2 Group Theory

Abstract

We prove that if two topologically free and entropy regular actions of countable sofic groups on compact metrizable spaces are continuously orbit equivalent, and each group either (i) contains a w-normal amenable subgroup which is neither locally finite nor virtually cyclic, or (ii) is a non-locally-finite product of two infinite groups, then the actions have the same sofic topological entropy. This fact is then used to show that if two free uniquely ergodic and entropy regular probability-measure-preserving actions of such groups are boundedly orbit equivalent then the actions have the same sofic measure entropy. Our arguments are based on a relativization of property SC to sofic approximations and yield more general entropy inequalities.

Keywords

Cite

@article{arxiv.2002.02397,
  title  = {Entropy, products, and bounded orbit equivalence},
  author = {David Kerr and Hanfeng Li},
  journal= {arXiv preprint arXiv:2002.02397},
  year   = {2022}
}

Comments

36 pages. Minor changes. To appear in Ergodic Theory Dynam. Systems. arXiv admin note: text overlap with arXiv:1912.02764

R2 v1 2026-06-23T13:33:21.266Z