Automorphisms of the Torelli complex and the complex of separating curves
Group Theory
2015-02-02 v3 Geometric Topology
Abstract
We compute the automorphism groups of the Torelli complex and the complex of separating curves for all but finitely many compact orientable surfaces. As an application, we show that the abstract commensurators of the Torelli group and the Johnson kernel for such surfaces are naturally isomorphic to the extended mapping class group.
Keywords
Cite
@article{arxiv.0909.4718,
title = {Automorphisms of the Torelli complex and the complex of separating curves},
author = {Yoshikata Kida},
journal= {arXiv preprint arXiv:0909.4718},
year = {2015}
}
Comments
43 pages, 12 figures