2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/33539I consider a semiclassical expansion of the scalar field in the warm inflation scenario. I study the evolution for the fluctuations of the metric around the Friedmann-Robertson-Walker one. The formalism predicts that, in the power-law expansion universe, the fluctuations of the metric decreases with time.Accepted for publication in Il Nuovo Cimento B, 5 pages, no figuresGeneral Relativity and Quantum Cosmologytext