2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/198806We show how $N=4, D=4$ duality of Montonen and Olive can be derived for all gauge groups using geometric engineering in the context of type II strings, where it reduces to T-duality. The derivation for the non-simply laced cases involves the use of some well known facts about orbifold conformal theories.8 pagesHigh Energy Physics - Theorytext