2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/220920In this note we propose the use of an alternate action for the open string tachyon on a non-BPS $D3$-brane. At the classical level this action is precisely equivalent to the more commonly used DBI action, but involves an additional coupling to dynamical world-volume gravity. We find that, for a FRW metric, exponential expansion occurs provided that the cosmological constant is positive. For anti de-Sitter solutions we find a periodically bouncing universe, and there are no accelerating trajectories for a theory with no cosmological constant. In specific cases the acceleration is terminated by the condensation of the open string tachyon, leading to a canonical inflationary trajectory at late times.5 pages. References addedGeneral Relativity and Quantum CosmologyCosmology and Nongalactic Astrophysicstext