2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/35955The general properties of the gravity wave backgrounds of cosmological origin are reviewed and briefly discussed, with emphasis on the relic background expected from an early pre-big bang phase typical of string cosmology models.13 pages, LATEX, three figures included using EPSFIG. Talk given at the "Second Edoardo Amaldi Conference on Gravitational Wawes" (CERN, 1-4 July 1997). To be published in the Proceedings (World Scientific, Singapore), eds E. Coccia et al. An updated collection of papers on the pre-big bang scenario is available at http://www.to.infn.it/teorici/gasperiniGeneral Relativity and Quantum CosmologyAstrophysicsHigh Energy Physics - PhenomenologyHigh Energy Physics - Theorytext