Geometry Seminar

This talk is on the topology of Symp(M), where Symp(M) is the symplectomorphism group of a symplectic rational surface M. We will illustrate our approach with the 5 point blowup of the projective plane. For an arbitrary symplectic form on this rational surface, we are able to determine the symplectic mapping class group and describe the answer in terms of the Dynkin diagram of Lagrangian sphere classes. We are also able to compute the fundamental group of Symp(M) for an open region of the symplectic cone. This is a joint work with Tian-Jun Li and Weiwei Wu. Speaker(s): Jun Li (U Michigan)