2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/201777We investigate the possibility that both the baryon asymmetry of the universe and the observed cold dark matter density are generated by decays of a heavy scalar field which dominates the universe before nucleosynthesis. Since baryons and cold dark matter have common origin, this mechanism yields a natural explanation of the similarity of the corresponding energy densities. The cosmological moduli and gravitino problems are avoided.12 pages, one figure; v2: matches version published in PLBHigh Energy Physics - Phenomenologytext