Kaluza-Klein cosmology from five-dimensional Lovelock-Cartan theory

Cristóbal Corral (ICN-UNAM)

Resumen: In the first part of this talk, we will review some aspects of gravitational theories with nonvanishing torsion, such as the Einstein-Cartan theory in four dimensions. The second part will be devoted to the Kaluza-Klein dimensional reduction of the Lovelock-Cartan theory in five-dimensional spacetime, with a compact dimension of S^1 topology. We present a new class of cosmological solutions of the Friedmann-Robertson-Walker class in the reduced spacetime. The torsion and the fields arising from the dimensional reduction induce a nonvanishing energy-momentum tensor in four dimensions. The solutions describe expanding, contracting, and bouncing universes. The model shows a dynamical compactification of the extra dimension in some regions of the parameter space.