Surface subgroups from homology

Calegari, Danny

doi:10.2140/gt.2008.12.1995

Download this article
	For screen
	For printing

Recent Issues

The Journal

Submission Guidelines

Submission Page

Policies for Authors

Ethics Statement

ISSN 1364-0380 (online)

ISSN 1465-3060 (print)

Author Index

To Appear

Other MSP Journals

Surface subgroups from homology

Danny Calegari

Geometry & Topology 12 (2008) 1995–2007

DOI: 10.2140/gt.2008.12.1995

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.

Keywords

hyperbolic group, surface subgroup, graph of groups, Thurston norm, rational polyhedron

Mathematical Subject Classification 2000

Primary: 20F65, 20F67

Secondary: 57M07

References

Publication

Received: 4 April 2008

Revised: 9 June 2008

Accepted: 8 June 2008

Published: 5 July 2008

Proposed: Benson Farb

Seconded: Joan Birman and Dave Gabai

Authors

Danny Calegari
Department of Mathematics Caltech Pasadena CA, 91125

Volume 12, issue 4 (2008)