Geometry, Topology and Dynamics Seminar
Sebastian Hensel
University of Chicago
The handlebody Torelli group
Abstract: The mapping class group of a surface has various
topologically motivated subgroups. In this talk we combine two of
them: the Torelli group (of those elements acting trivially on homology)
and the handlebody group (of those elements extending to a given handlebody).
We prove that it has an (infinite) generating set similar to the usual
Torelli group (answering a question of Joan Birman)
We also begin to develop a Johnson theory for the handlebody Torelli
group, and highlight some of the many open questions about this group. This
is joint work-in-progress with Andy Putman.
Monday April 27, 2015 at 3:00 PM in SEO 636