Colloquium

April 16, 2009

4:00 PM, BAC 102

Speaker: Justin Moore, Cornell University

Title:  Fast growth in Følner sets for Thompson's group $F$

While it is not known whether Thompson's group $F$ is amenable, I will establish a lower bound on the cardinality of Følner sets. In particular, I will demonstrate the following: There is a constant $C > 1$ such that if $A$ is a $C^{-4^n}$-F\o lner set in $F$, then $A$ contains at least $H(n)$ elements, where $H(0) = 0$ and $H(n+1) = 2^{H(n)}$.