2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/205156Using the pure spinor formalism on the world-sheet, we derive the T-duality rules for all target space couplings in an efficient manner. The world-sheet path integral derivation is a proof of the equivalence of the T-dual Ramond-Ramond backgrounds which is valid non-perturbatively in the string length over the curvature radius and to all orders in perturbation theory in the string coupling.7 pages, accepted for publication in PLBHigh Energy Physics - Theorytext