Title    name
Geometric Topology Fair 2017
  Speaker Hidetoshi Masai
  Date 2017-05-11
  Place KAIST
  File  의 1 번째 Real Media 동영상입니다.   
Abstract : Calegari-Sun-Wang defined a covering relation on the set of mapping classes of surface automorphisms. A mapping class $phi$ covers $psi$ if $phi$ is a lift of a power of $psi$ with respect to a finite covering of underlying surfaces. Commensurability given by this covering is called fibered commensurability. In this talk, we analogously define a covering relation on the set of outer automorphisms of free groups, and discuss its properties. This is a joint work with Ryosuke Mineyama.