Geometry, Topology and Dynamics Seminar
Pierre Py
University of Chicago
Quasi-morphisms and area-preserving homeomorphisms
Abstract: I will recall the notion of a quasi-morphism on a group and describe a few examples of quasi-morphisms defined on groups of Hamiltonian diffeomorphisms of surfaces. Then we will try to answer the following question: which quasi-morphisms on these groups are continuous for the C0-topology? This question is related to the problem of the simplicity of the group of compactly supported area-preserving homeomorphisms of the disc. This is based on a joint work with M. Entov and L. Polterovich. This is also related to a recent work of Le Roux.
Monday March 2, 2009 at 3:00 PM in SEO 612