2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/197474We review physical motivations, phenomenological consequences, and open problems of the so-called pre-big bang scenario in superstring cosmology.250 pages, latex, 34 figures included using epsfigHigh Energy Physics - TheoryAstrophysicsGeneral Relativity and Quantum CosmologyHigh Energy Physics - Phenomenologytext