Title: Rationality of Rotation Numbers for elements of Thompson's Group $T$
Speaker: Jan-Li Lin
Speaker Info: University of Notre Dame
Special Note: We will go to dinner after the talk.
The group $T$ is defined by Richard Thompson in 1965. It is a group of homeomorphisms of the circle. It is shown by E. Ghys and V. Sergiescue in 1987 that the rotation number of any element of this group is rational, and that every rational number is achieved. However, their proof is very indirect. In this talk, I will present a combinatorial, more direct proof. This is joint work with Jeff Diller. Note: Although the proof is motivated by our work in complex dynamics, there will be no complex dynamics in this talk.Date: Tuesday, February 4, 2014