Event calendar file
School of Mathematics Seminars and Lectures
Thin Groups and Expansion
by Prof. Peter Sarnak (Princeton University and Institute for Advanced Study, USA)
Tuesday, May 22, 2012
from
to
(Asia/Kolkata)
at Colaba Campus ( AG-66 )
at Colaba Campus ( AG-66 )
| Description |
Infinite index subgroups of matrix groups like SL(n,Z) which are Zariski dense in SL(n), arise in many geometric and diophantine problems (eg reflection groups, groups connected with elementary geometry such as integral apollonian packings, monodromy groups of families of algebraic varieties..). One of the key features needed for number theoretic applications is that these groups obey some form of the Ramanujan Conjectures. In this context this asserts that certain congruence graphs associated with these groups are expanders. We will introduce these ideas and review some of the many recent developments. |
