Speaker: Dr. Gang Liu (Berkeley)

Time: 9:30-11:30 am, June 21 (Friday)

Venue: Room 29 at Quan Zhai, BICMR

Abstract: Let M be a complete noncompact three manifold with nonnegative Ricci curvature(not necessarily orientable). We show M is either diffeomorphic to R^3 or the universal cover splits as a Riemann product of a real line and a two dimensional surface with nonnegative Gaussian curvature. As a corollary, this confirms a conjecture of Milnor in dimension three.