May 7, 2008
Klas Markström (Umeaå): Azuma-Hoeffding inequalities for matrix martingales and random expanders
Abstract:
In this talk I will discuss a concentration inequality for random
sequences of hermitian matrices. As an application I will prove a sharp
version of Alon-Roichman's theorem about the expansion properties of
random Cayley graphs, and an extension of this theorem to random
vertex-transitive graphs.