groups and dynamics (abstract)

Texas A&M University, Department of Mathematics, 216 Milner Hall, 23rd of September and 14th of October 2009, 3:00-3:50

Groups and Dynamics Seminar

A geometric approach to Kazhdan's property (T) and Kazhdan constants

Piotr Nowak of Texas A&M University

We will discuss a geometric approach to property (T). In particular we will prove a theorem of A. Zuk that groups with a certain spectral condition on the set of generators have property (T). We will also improve Zuk's estimate of Kazhdan's constants in this case to an optimal estimate for the case of certain groups related to A_2-tilde buildings.