4:00 pm Monday, April 21, 2014
Topology Seminar: Slim Unicorns and Dismantling Graphs
by Sebastian Hensel (University of Chicago) in HB 427
In this talk I'll present two (related) combinatorial techniques that can be used to study the curve and arc graph of a surface and thus, in the long run, also the mapping class group. One is an explicit construction of paths in the arc graph (unicorn paths) that yield a very short proof of hyperbolicity of arc and curve graphs (this is joint with Piotr Przytycki and Richard Webb). The other is a combinatorial property (dismantlability) which one can think of as a strengthening of contractability that is extremely useful when studying finite group actions. Arc, disk and sphere graphs have this property, and it can be used to study mapping class groups (and Out(F_n)). This is joint work with Piotr Przytycki and Damian Osajda. Host Department: Rice University-Mathematics
Submitted by andyp@rice.edu |
