2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/220918Using the pure spinor formalism, we compute the tree-level correlation functions for three strings, one closed and two open, in N=1 D=10 superspace. Expanding the superfields in components, the respective terms of the effective action for the type I supergravity are obtained. All terms found agree with the effective action known in the literature. This result gives one more consistency test for the pure spinor formalism.25 pagesHigh Energy Physics - Theorytext