Shear and Vorticity in an Accelerating Brans-Dicke Lambda-Universe with Torsion

英文摘要：

We study accelerating Universes with power-law scale-factors. We include shear and vorticity, a cosmological "constant" term, and spin from torsion, as in Einstein-Cartan's theory when a scalar-field of Brans-Dicke type acts in the model. We find a "no-hair" result, for shear and vorticity; we also make contact with the alternative Machian picture of the Universe. Keywords: Cosmology; Einstein; Brans-Dicke; Cosmological term; Shear; Spin; Vorticity; Inflation; Einstein-Cartan; Torsion; Accelerating Universe