English

Jordan property for homeomorphism groups and almost fixed point property

Algebraic Topology 2022-10-14 v1 Group Theory Geometric Topology

Abstract

We study properties of continuous finite group actions on topological manifolds that hold true, for any finite group action, after possibly passing to a subgroup of index bounded above by a constant depending only on the manifold. These include the Jordan property, the almost fixed point property, as well as bounds on the discrete symmetry group. Most of our results apply to manifolds satisfying some restriction such as having nonzero Euler characteristic or having the integral homology of a sphere. For an arbitrary topological manifold XX such that H(X;Z)H_*(X;{\mathbf Z}) is finitely generated, we prove the existence a constant CC with the property that for any continuous action of a finite group GG on XX such that every gGg\in G fixes at least on point of XX, there is a subgroup HGH\leq G satisfying [G:H]C[G:H]\leq C and a point xXx\in X which is fixed by all elements of HH.

Keywords

Cite

@article{arxiv.2210.07081,
  title  = {Jordan property for homeomorphism groups and almost fixed point property},
  author = {Ignasi Mundet i Riera},
  journal= {arXiv preprint arXiv:2210.07081},
  year   = {2022}
}

Comments

15 pages, comments welcome

R2 v1 2026-06-28T03:33:45.192Z