2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48296We investigate the implications of the standard Big-Bang Nucleosynthesis constraint on the number of light neutrinos in the framework of the two four-neutrino schemes that are favored by the results of neutrino oscillation experiments.15 pages. Talk presented by C. Giunti at the Symposium "New Era in Neutrino Physics", Tokyo Metropolitan University, Japan, 11-12 June, 1998High Energy Physics - Phenomenologytext