Surface subgroups from homology
Group Theory
2008-07-22 v2 Geometric Topology
Abstract
Let G be a word-hyperbolic group, obtained as a graph of free groups amalgamated along cyclic subgroups. If H_2(G;Q) is nonzero, then G contains a closed hyperbolic surface subgroup. Moreover, the unit ball of the Gromov-Thurston norm on H_2(G;R) is a finite-sided rational polyhedron.
Cite
@article{arxiv.0803.4137,
title = {Surface subgroups from homology},
author = {Danny Calegari},
journal= {arXiv preprint arXiv:0803.4137},
year = {2008}
}
Comments
9 pages; version 2: typos corrected