Quasi-homomorphisms and stable lengths in mapping class groups
arXiv:math/0307362 · doi:10.1090/S0002-9939-04-07508-2
Abstract
We give elementary applications of quasi-homomorphisms to growth problems in groups. A particular case concerns the number of torsion elements required to factorise a given element in the mapping class group of a surface.
Revised to include a discussion of weak bounded generation, both in general and for mapping class groups; now 8 pages