Title:
Almost Ricci-flat 4-manifolds
Abstract:
A manifold is almost Ricci-flat if it admits a sequence of Riemannian metrics with diameter one, for which the Ricci curvature goes to zero uniformly. I will describe results about the topology and geometry of almost Ricci-flat 4-manifolds in the noncollapsed case (joint work with Vitali Kapovitch) and in the collapsed case.