2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/53476Recently, string theory on Calabi--Yau manifolds was constructed and was shown to be a fully consistent, space--time supersymmetric string theory. The physically interesting case is the case of three generations. Intriguingly, it appears at the present that there is a unique manifold which gives rise to three generations. We describe in this paper a full fledged string theory on this manifold in which the complete spectrum and all the Yukawa couplings can be computed exactly.Priceton preprint, December 1987. Note: this paper appeared only as a preprint on December 1987. Recently, a number of physicists have suggested its republication due to the fact that old preprints are not easily accesible. This is the original tex file used at that timeHigh Energy Physics - Theorytext