## Dynamics, Geometry, & Groups Seminar

### Thursday, November 12th, 2020

**Time:** 2:00 p.m** Place:**

**Speaker:** Lei Chen (California Institute of Technology)

**Title:** Nielsen realization problem for the mapping class group.

**Abstract:** Nielsen realization problem for the mapping class group Mod(Sg) asks whether the natural projection pg:Homeo+(Sg)→Mod(Sg) has a section. Moreover, we also care about the realization of subgroups of Mod(S_g). In this talk, I will explain some ideas towards this problem. It will use some rotation number results and fixed points theory.