Realisation and dismantlability
Geometric Topology
2014-11-11 v1 Group Theory
Abstract
We study dismantling properties of the arc, disc and sphere graphs. We prove that any finite subgroup H of the mapping class group of a surface with punctures, the handlebody group, or Out(F_n) fixes a filling (resp. simple) clique in the appropriate graph. We deduce realisation theorems, in particular the Nielsen Realisation Problem in the case of a nonempty set of punctures. We also prove that infinite H have either empty or contractible fixed point sets in the corresponding complexes. Furthermore, we show that their spines are classifying spaces for proper actions for mapping class groups and Out(F_n).
Cite
@article{arxiv.1205.0513,
title = {Realisation and dismantlability},
author = {Sebastian Hensel and Damian Osajda and Piotr Przytycki},
journal= {arXiv preprint arXiv:1205.0513},
year = {2014}
}
Comments
33 pages, 3 figures