Quasi-morphisms on Surface Diffeomorphism groups
- Series
- Geometry Topology Seminar
- Time
- Monday, March 28, 2022 - 14:00 for 1 hour (actually 50 minutes)
- Location
- Speaker
- Jonathan Bowden – jonathan.bowden@mathematik.uni-regensburg.de
We discuss the problem of constructing quasi-morphisms on the group of diffeomorphisms of a surface that are isotopic to the identity, thereby resolving a problem of Burago-Ivanov-Polterovich from the mid 2000’s. This is achieved by considering a new kind of curve graph, in analogy to the classical curve graph first studied by Harvey in the 70’s, on which the full diffeomorphism group acts isometrically. Joint work with S. Hensel and R. Webb.