Generators for the kernel of the integral Burau representation
Tara Brendle (U Glasgow)
Wednesday 23rd January, 2013 16:00-17:00 204
The "integral Burau representation" is the classical Burau representation of the braid group evaluated at t = -1. The kernel of the integral Burau representation can be identified with the so-called hyperelliptic Torelli subgroup of the mapping class group of a surface. We will describe a set of generators for this group, verifying a conjecture of Hain with applications in algebraic geometry. In the process, we will describe a new method for finding presentations of finite-index subgroups of finitely presented groups.