[Binghamton Geometry/Topology Seminar] Geometry/Topology Seminar

[Christoforos Neofytidis]

BINGHAMTON GEOMETRY/TOPOLOGY SEMINAR

   Date: Thursday, November 10th, 2016

   Time: 2.50 pm

   Place: Whitney Hall, Room 100E

   Speaker: Bena Tshishiku (Harvard University)

   Title: Obstructions to Nielsen realization

Abstract: Let M be a manifold, and let Mod(M) be its mapping class group.
The Nielsen realization problem for diffeomorphisms asks, “Can a given
subgroup G<Mod(M) be lifted to the diffeomorphism group Diff(M)?” This
question about group actions is related to a question about flat
connections on fiber bundles with fiber M. In the case M is a closed
surface, the answer is “yes" for finite G (by work of Kerckhoff) and “no"
for G=Mod(M) (by work of Morita). For most infinite G<Mod(M), we have no
idea. I will discuss some obstructions that can be used to show that
certain groups don’t lift. Some of this work is joint with Nick Salter.

NOTE:  The seminar has a webpage where the semester's program is listed:

http://www2.math.binghamton.edu/p/seminars/topsem