Cosmological solution through gravitational decoupling in Brans-Dicke gravity

Abstract

In this paper, we compute an anisotropic cosmological solution through a minimal geometric deformation on a non-static spherical spacetime in the framework of self-interacting Brans-Dicke theory. The transformation of the radial component decouples the field equations into two arrays such that the influence of the anisotropic source is limited to one set only. We use FLRW universe model to obtain a solution of the system governed by the isotropic matter source. For this purpose, power-law models of the scale factor as well as massive scalar field are assumed while isotropic pressure and density are related via barotropic equation of state. The decoupling function, appearing in the other set, is evaluated through the conservation equation of the anisotropic source. Finally, we investigate the physical behavior, viability and stability of the extended FLRW solution for different values of the equation of state parameter. It is concluded that the solution is viable and stable for the massless scalar field and the radiation dominated universe.