EVENT DETAILS AND ABSTRACT

Title: Sum-product estimates and expanders
Speaker: Professor Alex Gamburd
Speaker Info: UC Santa Cruz
Brief Description:
Special Note: Please note special time
Abstract:

Using tools from additive combinatorics, in particular sum-product estimates, we prove that Cayley graphs of SL(2,p) are expanders with respect to the projection of any fixed elements in SL(2, Z) generating a non-elementary subgroup, and with respect to generators chosen at random in SL(2, p). Uniform spectral gap bounds for finitely generated subgroups of SU(2) will also be presented. This is joint work with Jean Bourgain.