Early universe in Brans-Dicke cosmology

Abstract

For zero-curvature Robertson-Walker models, Einstein's field equations in Brans-Dicke theory are investigated. Two exact solutions are obtained for two different phases, viz. inflationary phase and radiation-dominated phase by using "gamma-law" equation of state p = (γ - 1)ρ in which γ varies continuously as the universe expands. Some physical properties of the cosmological models are also discussed.