# Selberg plays ping-pong

 Mathematical Conversations Topic: Selberg plays ping-pong Speaker: Christopher Brav Affiliation: Member, School of Mathematics Date: Wednesday, December 11 Time/Room: 6:00pm - 7:00pm/West Bldg. Lect. Hall

We describe a method of Selberg for constructing fundamental domains for discrete groups of $\mathrm{SL}(n,\mathbb R)$ in terms of trace inequalities. We show how these Selberg domains can be used to play ping-pong, establishing freeness of some hypergeometric monodromy groups. http://www.math.ias.edu/~nicks/conversations.html