2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/202995Using a recently introduced 5D Riemann flat metric, we investigate the possibility of introducing dissipation in the dynamics of the inflaton field on an effective 4D FRW metric, in the framework of the STM theory of gravity.Final version, to be published in Phys. Lett. BGeneral Relativity and Quantum Cosmologytext