Fluid and scalar field representations in the Brans-Dicke theory: cosmological scenarios

The Brans-Dicke scalar-tensor cosmological models are studied in both Einstein and Jordan frames, using hydrodynamical and self-interacting scalar field representations of the energy-momentum tensor, leading to the same background solutions. The main features of the corresponding cosmological scenarios are determined. In many cases, we identify a transition from decelerated to accelerated regimes. The properties of the self-interacting scalar field, including the corresponding potential, are determined. Finally, some possible realistic configurations are analyzed.