Homotopy Self-Equivalences of Four-Manifolds

Abstract

In this thesis, we study the group of base-point preserving homotopy classes of homotopy self-equivalences of a four-manifold. Based on the approach of Hambleton and Kreck, an explicit description of this group is obtained when the fundamental group of the manifold is either a free group or a two-dimensional Poincare duality group. As a byproduct, a classification of such four-manifolds up to s-cobordism is obtained by using the modified surgery theory of Kreck.