Quasi-homomorphisms on mapping class groups
Group Theory
2007-05-23 v1 Geometric Topology
Abstract
We refine the construction of quasi-homomorphisms on mapping class groups. It is useful to know that there are unbounded quasi-homomorphisms which are bounded when restricted to particular subgroups since then one deduces that the mapping class group is not boundedly generated by these subgroups. In this note we enlarge the class of such subgroups. The generalization is motivated by considerations in first order theory of free groups.
Cite
@article{arxiv.math/0702273,
title = {Quasi-homomorphisms on mapping class groups},
author = {Mladen Bestvina and Koji Fujiwara},
journal= {arXiv preprint arXiv:math/0702273},
year = {2007}
}