The Topology of Open Manifolds with Nonnegative Ricci Curvature
  We survey all results concerning the topology of complete noncompact Riemannian manifolds with nonnegative Ricci curvature that have no additional conditions other than restrictions to the dimension, volume growth or diameter growth of the manifold. We will also present relevant examples and list open problems. 
Zhongmin Shen and Christina Sormani