School of Mathematical Sciences

Department Colloquium

Schreiber 006, 12:15

CUNY Graduate Center

After introducing expander graphs and briefly discussing Lubotzky-Weiss

Abstract:

Independence Problem for groups and expanders I will talk about recent

developments pertaining to establishing the expansion property for congruence

quotients of thin groups --discrete subgroups of semi-simple groups which are

Zariski dense but of infinite index. This expansion property can be viewed as a

far-reaching generalization of the strong approximation theorem and has many

applications.

Coffee will be served at 12:00 before the lecture

at Schreiber building 006