2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/163087The purpose of this paper is to describe a general and simple setting for defining $(g,p+q)$-string operations on a Poincaré duality space and more generally on a Gorenstein space. Gorenstein spaces include Poincaré duality spaces as well as classifying spaces or homotopy quotients of connected Lie groups. Our presentation implies directly the homotopy invariance of each $(g,p+q)$-string operation as well as it leads to explicit computations.30 pages and 2 figuresAlgebraic TopologyQuantum Algebra55P35, 54N45, 55N33, 17A65, 81T30, 17B55text