An extended frame for cosmology by integrable Weyl geometry

A conservative extension of general relativity by integrable Weyl geometry is formulated, and a new class of cosmological models ({\em Weyl universes}) is introduced and studied. A short discussion of how these new models behave in the light of observational evidence follows. It turns out that the subclass of Weyl universes with positive ex-ante curvature of spatial sections ({\em Einstein-Weyl universes}) forms an empirically contentful conceptual frame for cosmology. Recent high precision data (supernovae Ia, quasar frequencies, microwave background) are well represented in this type of Weyl geometry and several of the anomalies of the standard approach are avoided or become meaningless.