groups and dynamics (abstract)

Texas A&M University, Department of Mathematics, 216 Milner Hall, 24th of October 2007, 3:00-3:50

Groups and Dynamics Seminar

Local similarities and the Haagerup Property

Bruce Hughes of Vanderbilt University

I will introduce a new class of groups - finitely determined groups of local similarities on a compact ultrametric space - and prove that they have the Haagerup property (that is, they are a-T-menable in the sense of Gromov). The class includes Thompson's groups, which have already been shown to have the Haagerup property by Dan Farley, as well as many other groups acting on boundaries of trees.