English

The dynamical hierarchy for Roelcke precompact Polish groups

Logic 2016-02-22 v3 Dynamical Systems

Abstract

We study several distinguished function algebras on a Polish group GG, under the assumption that GG is Roelcke precompact. We do this by means of the model-theoretic translation initiated by Ben Yaacov and Tsankov: we investigate the dynamics of 0\aleph_0-categorical metric structures under the action of their automorphism group. We show that, in this context, every strongly uniformly continuous function (in particular, every Asplund function) is weakly almost periodic. We also point out the correspondence between tame functions and NIP formulas, deducing that the isometry group of the Urysohn sphere is \Tame\UC\Tame\cap\UC-trivial.

Keywords

Cite

@article{arxiv.1405.4613,
  title  = {The dynamical hierarchy for Roelcke precompact Polish groups},
  author = {Tomás Ibarlucía},
  journal= {arXiv preprint arXiv:1405.4613},
  year   = {2016}
}

Comments

25 pages

R2 v1 2026-06-22T04:17:34.703Z