%0 Journal Article
%T Generalized fibre sums of 4-manifolds and the canonical class
%A M. J. D. Hamilton
%J Mathematics
%D 2009
%I arXiv
%X In this paper we determine the integral homology and cohomology groups of a closed 4-manifold X obtained as the generalized fibre sum of two closed 4-manifolds M and N along embedded surfaces of genus g and self-intersection zero. If the homologies of the 4-manifolds are torsion free and the surfaces represent indivisible homology classes, we derive a formula for the intersection form of X. If in addition the 4-manifolds M and N are symplectic and the surfaces symplectically embedded we derive a formula for the canonical class of the symplectic fibre sum.
%U http://arxiv.org/abs/0907.2671v4