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4:00 pm Monday, March 10, 2014 Topology Seminar: Rigidity of diffeomorphism groupsby Sebastian Hurtado (Berkeley) in HB 427- Let Diff_0(M) be the group of diffeomorphisms of a closed manifold M which are isotopic to the identity. As a discrete group, Diff_0(M) is somewhat rigid: Diff_0(M) is a simple group and Filipkiewicz proved that Diff_0(M) and Diff_0(N) are isomorphic (as discrete groups) if and only if M and N are diffeomorphic. I'll talk about these theorems, about the concept of distortion in geometric group theory and about how to use this concept to prove that any homomorphism of discrete groups P : Diff_0(M) ---> DIff_0(N) is in fact continuous.
Submitted by andyp@rice.edu |