Bounded orbits and global fixed points for groups acting on the plane
Dynamical Systems
2014-10-01 v2 Geometric Topology
Abstract
Let G be a group acting on the plane by orientation-preserving homeomorphisms. We show that if for some k>0 there is a ball of radius r > k/\sqrt{3} such that each point x in the ball satisfies |gx -hx| < k for all g, h in G, and the action of G satisfies a nonwandering hypothesis, then the action has a global fixed point. In particular, any group of measure-preserving orientation preserving homeomorphisms of the plane with uniformly bounded orbits has a global fixed point. The constant k/\sqrt{3} is sharp. We also show that a group acting on the plane with orbits bounded as above is left orderable.
Cite
@article{arxiv.1103.5060,
title = {Bounded orbits and global fixed points for groups acting on the plane},
author = {Kathryn Mann},
journal= {arXiv preprint arXiv:1103.5060},
year = {2014}
}
Comments
v2 reflects published version. Added argument in section 2, results unchanged