English

Distal strongly ergodic actions

Dynamical Systems 2020-09-25 v3

Abstract

Let η\eta be an arbitrary countable ordinal. Using results of Bourgain and Gamburd on compact systems with spectral gap we show the existence of an action of the free group on three generators F3F_3 on a compact metric space XX, admitting an invariant probability measure μ\mu, such that the resulting dynamical system (X,μ,F3)(X, \mu, F_3) is strongly ergodic and distal of rank η\eta. In particular this shows that there is a F3F_3 system which is strongly ergodic but not compact. This result answers the open question whether such actions exist.

Keywords

Cite

@article{arxiv.1803.01844,
  title  = {Distal strongly ergodic actions},
  author = {Eli Glasner and Benjamin Weiss},
  journal= {arXiv preprint arXiv:1803.01844},
  year   = {2020}
}

Comments

A section is added where we show the existence of distal strongly ergodic $F_3$-systems of arbitrary countable rank. A few corrections of some mathematical errors and some misprints

R2 v1 2026-06-23T00:42:50.708Z