2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/148319We obtain cosmological four dimensional solutions of the low energy effective string theory by reducing a five dimensional black hole, and black hole--de Sitter solution of the Einstein gravity down to four dimensions. The appearance of a cosmological constant in the five dimensional Einstein--Hilbert action produces a special dilaton potential in the four dimensional effective string action. Cosmological scenarios implemented by our solutions are discussed. (Talk presented at: ``27th Symposium on the Theory of Elementary Particles'' Wendisch--Rietz, September 7--11, 1993)9 Pages, 4 figures, Latex, epsfig.sty, SLAC--PUB--6411 T , additional referencesHigh Energy Physics - Theorytext