English

Every Borel automorphism without finite invariant measures admits a two-set generator

Dynamical Systems 2017-06-07 v2

Abstract

We show that if an automorphism of a standard Borel space does not admit finite invariant measures, then it has a two-set generator modulo the sigma-ideal generated by wandering sets. This implies that if the entropies of invariant probability measures of a Borel system are all less than log(k), then the system admits a k-set generator, and that a wide class of hyperbolic-like systems are classified completely at the Borel level by entropy and periodic points counts.

Keywords

Cite

@article{arxiv.1508.02335,
  title  = {Every Borel automorphism without finite invariant measures admits a two-set generator},
  author = {Michael Hochman},
  journal= {arXiv preprint arXiv:1508.02335},
  year   = {2017}
}

Comments

57 pages. v2: some corrections to proofs, statements unchanged