Roberto Conti: On groups and heat properties

Abstract: Somewhat motivated by the original approach of J.-B. Fourier to solve the heat equation, we venture into new properties of countable groups that can be expressed using certain completely positive multipliers and convergence of Fourier series. Examples will be provided to illustrate the various aspects. A challenging goal not quite in sight would be to obtain yet another characterization of groups with Kazhdan's property (T). Based on joint work in progress with E. Bédos.