English

Highly faithful actions and dense free subgroups in full groups

Group Theory 2017-03-10 v2 Dynamical Systems

Abstract

In this paper, we show that every measure-preserving ergodic equivalence relation of cost less than m comes from a "rich" faithful invariant random subgroup of the free group on m generators, strengthening a result of Bowen which had been obtained by a Baire category argument. Our proof is completely explicit: we use our previous construction of topological generators for full groups and observe that these generators induce a totally non free action. We then twist this construction so that the action is moreover amenable onto almost every orbit and highly faithful.

Keywords

Cite

@article{arxiv.1509.03584,
  title  = {Highly faithful actions and dense free subgroups in full groups},
  author = {François Le Maître},
  journal= {arXiv preprint arXiv:1509.03584},
  year   = {2017}
}

Comments

New version incorporating referee's comments. To appear in Groups, Geometry and Dynamics

R2 v1 2026-06-22T10:54:46.553Z