缅北强奸

Title: Embeddings of rational balls

Abstract:聽The generalised rational blowdown operation of Fintushel-Stern and J. Park involves removing a plumbed submanifold bounded by the lens space L(p^2,pq-1) from a smooth 4-manifold, and replacing it by a rational homology 4-ball. For this reason and others there has been some interest in embeddings of these rational balls in various 4-manifolds. I will discuss some results in this area including examples of rational balls which embed smoothly but not symplectically in CP^2.