On distortion in groups of homeomorphisms
Abstract
Let X be a path-connected topological space admitting a universal cover. Let Homeo(X,a) denote the group of homeomorphisms of X preserving degree one cohomology class a. We investigate the distortion in Homeo(X,a). Let g be an element of Homeo(X,a). We define a Nielsen-type equivalence relation on the space of g-invariant Borel probability measures on X and prove that if a homeomorphism g admits two nonequivalent invariant measures then it is undistorted. We also define a local rotation number of a homeomorphism generalising the notion of the rotation of a homeomorphism of the circle. Then we prove that a homeomorphism is undistorted if its rotation number is nonconstant.
Cite
@article{arxiv.1111.1449,
title = {On distortion in groups of homeomorphisms},
author = {Światosław Gal and Jarek Kędra},
journal= {arXiv preprint arXiv:1111.1449},
year = {2011}
}
Comments
This paper mostly overlaps with part of arXiv:math/1105.0825. It is the version that is going to appear in print