Quasi-homomorphisms and stable lengths in mapping class groups
Abstract
Description
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
Revised to include a discussion of weak bounded generation, both in general and for mapping class groups; now 8 pages