2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/172034We summarize the structure of N=2 multi-instanton and string loop corrections to the Kähler potential and the gauge kinetic function in type I toroidal orbifold models. For that aim, we exploit perturbative calculations of the physical gauge couplings on the heterotic dual, whenever such a perturbative description is available.Parallel talk at 34th International Conference on High Energy Physics (ICHEP08), Philadelphia, USA, July 2008. 5 pagesHigh Energy Physics - TheoryThe structure of N=2 multi-instanton and string-loop corrections in toroidal orbifold modelstext