English

Central Extensions of Word Hyperbolic Groups

Group Theory 2008-02-03 v1

Abstract

Thurston has claimed (unpublished) that central extensions of word hyperbolic groups by finitely generated abelian groups are automatic. We show that they are in fact biautomatic. Further, we show that every 2-dimensional cohomology class on a word hyperbolic group can be represented by a bounded 2-cocycle. This lends weight to the claim of Gromov that for a word hyperbolic group, the cohomology in every dimension is bounded.

Keywords

Cite

@article{arxiv.math/9507201,
  title  = {Central Extensions of Word Hyperbolic Groups},
  author = {Walter Neumann and Lawrence Reeves},
  journal= {arXiv preprint arXiv:math/9507201},
  year   = {2008}
}

Comments

Plain Tex, 9 pages, no figures