Por João Baptista.

Kaluza-Klein models are an old line of research seeking a geometrical unification of the different physical forces. During the 1980s they were largely set aside, due both to specific technical difficulties and to the trend towards superstrings. In this talk I will re-examine two important technical difficulties traditionally imputed to Kaluza-Klein and suggest that, in fact, progress may be possible within a slightly more general geometrical framework. On the physics side, I will talk about mass generation for gauge bosons, chiral fermions, inflation and the very small value of the cosmological constant. On the geometry side, I will talk about scalar curvature in general Riemannian submersions, Diff(K)-gauge theories, unstable Einstein metrics and left-invariant metrics on Lie groups.