Justin Moore : Fast Growth in the Folner Function for Thompson's Group $F$.

Posted by Christian Rosendal , part of the Logic Seminar.

At

Nov. 10, 2009, 4 p.m.

In

SEO 612

Abstract

While it is not known whether Thompson's group $F$ is amenable, I will establish a lower bound on the cardinality of its Foelner sets. In particular, I will demonstrate the following: There is a constant $C > 1$ such that if $A$ is a $C^{-n}$-Foelner set in $F$, then $A$ contains at least $H(n)$ elements, where $H(0)=0$ and $H(n+1)=2^{H(n)}$.