English

The group of homeomorphisms of the Cantor set has ample generics

Dynamical Systems 2014-02-26 v2 Group Theory Logic

Abstract

We show that the group of homeomorphisms of the Cantor set H(K)H(K) has ample generics, that is, for every mm the diagonal conjugacy action g(h1,h2,...,hm)=(gh1g1,gh2g1,...,ghmg1)g\cdot(h_1,h_2,..., h_m)=(gh_1g^{-1},gh_2g^{-1},..., gh_mg^{-1}) of H(K)H(K) on H(K)mH(K)^m has a comeager orbit. This answers a question of Kechris and Rosendal. We show that the generic tuple in H(K)mH(K)^m can be taken to be the limit of a certain projective Fraisse family. We also present a proof of the existence of the generic homeomorphism of the Cantor set in the context of the projective Fraisse theory.

Keywords

Cite

@article{arxiv.1104.3340,
  title  = {The group of homeomorphisms of the Cantor set has ample generics},
  author = {Aleksandra Kwiatkowska},
  journal= {arXiv preprint arXiv:1104.3340},
  year   = {2014}
}

Comments

final version, to appear in Bulletin of the London Mathematical Society