2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/194420We study gravitational waves generated during the inflationary epoch in presence of a decaying cosmological parameter on a 5D geometrical background which is Riemann flat. Two examples are considered, one with a constant cosmological parameter and the second with a decreasing one.accepted in Phys. Lett. BGeneral Relativity and Quantum CosmologyHigh Energy Physics - Theorytext