[Binghamton Geometry/Topology Seminar] Geometry & Topology seminar

[somnath at math.binghamton.edu]

BINGHAMTON GEOMETRY/TOPOLOGY SEMINAR

*Date:*  Thursday, March 6th, 2013

*Time:*  2:50-3:50pm
*Place:*  Library North 2205 followed by coffee/tea in the Anderson
Reading Room.

*Speaker: ** *Thomas Koberda (Yale University)
*Title: * Anti-trees and right-angled Artin subgroups of braid groups.

*Abstract:* I will discuss a result which shows that every right-angled
Artin group can be embedded in a planar braid group. I will then give some
examples of closed hyperbolic 4-manifold groups which were previously not
known to embed in braid groups, as well as some applications to the
algebra of right-angled Artin groups. Finally, I will discuss some
applications to decision problems for finitely presented subgroups of
braid groups, showing that there exists a finitely presented subgroup of a
braid group with an unsolvable conjugacy problem and an unsolvable
membership problem, as well as the fact that the isomorphism problem for
finitely presented subgroups of braid groups is unsolvable. This work is
joint with Sang-hyun Kim.