Weakly Commensurable Groups
Andrei Rapinchuk, University of Virginia
Location: Stevenson 5211
The notion of weak commensurability (of Zariski-dense subgroups of semi-simple algebraic groups) was introduced in the ongoing joint work with Gopal Prasad on length-commensurable and isospectral locally symmetric spaces. We were able to determine when two arithmetic subgroups are weakly commensurable. This led to various geometric results, some of which are related to the famous question "Can one hear the shape of a drum?" Tea at 3:30 pm in SC 1425.