2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/60183In the symplectic category there is a `connect sum' operation that glues symplectic manifolds by identifying neighborhoods of embedded codimension two submanifolds. This paper establishes a formula for the Gromov-Witten invariants of a symplectic sum Z=X#Y in terms of the relative GW invariants of X and Y. Several applications to enumerative geometry are given.AMS-Latex, 66 pages with 3 eps figures (typos fixed in the introduction)Symplectic GeometryAlgebraic GeometryDifferential Geometrytext