Algorithmic aspects of homeomorphism problems

Abstract

We will describe some results regarding the algorithmic nature of homeomorphism problems for manifolds; in particular, the following theorem. Theorem 1: Every PL or smooth simply connected manifold M^n of dimension n at least 5 can be recognized among simply connected manifolds. That is, there is an algorithm to decide whether or not another simply connected manifold is Top, PL or Diff isomorphic to M. Moreover, an analogous statement is true for embeddings in codimension at least three: one can algorithmically recognize any given embedding of one simply connected manifold in another up to isomorphism of pairs, or up to isotopy, if the codimension of the embedding is not two.