Ramanujan Graphs

The theory of Ramanujan graphs has become significant in communication theory in that it solves an important extremal problem. However, their explicit construction is still shrouded in mystery. At present, all explicit constructions rely heavily on number theory, algebraic geometry and representation theory. In this talk, we will give a leisurely survey of this exciting area. The talk should be accessible to undergraduates.

Refreshments will be served at 2:45 p.m. in the Faculty Lounge, Math Annex (Room 1115).