2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/53043Based on the recent developments of explicit computations at 2 loops in superstring theory in the covariant RNS formalism, we propose an explicit formula for the arbitrary loop 4-particle amplitude in superstring theory. We prove that this formula passes two very difficult tests: modular invariance and factorization. If proved, this shows that superstring theory is not only finite order by order in perturbation theory but is also exceptionally simple.LaTex file, 11 pages, no figureHigh Energy Physics - Theorytext