2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/173531The time equation associated to the Dirac Equation (DE) is studied for the radiation-dominated Friedmann-Robertson-Walker (FRW) universe. The results are analysed for small and large values of time. We also incorporate the corrections of the paper studied by Zecca [1] for the matter-dominated FRW universe.General Relativity and Quantum Cosmologytext