Exotic Diffeomorphisms: A Conversation Between Equivariant Stable Homotopy and Spin Four-Manifolds

Abstract: Exotic diffeomorphisms are those diffeomorphisms which are in the same path component as the identity of the homeomorphism group, but are not in the identity component in the diffeomorphism group. Several people have found the boundary Dehn twist is an exotic diffeomorphism on some four manifolds. This talk will be on the methods I used to find a novel result where we use tools from equivariant stable homotopy to detect that the Dehn twist is not isotopic to the identity on K3#K3\B^4.