Cosmological solutions through gravitational decoupling in \(f({\mathcal {R}},{\mathcal {T}},{\mathcal {R}}_{\textrm{ab}}{\mathcal {T}}^{\textrm{ab}})\) gravity

Abstract

In this paper, we adopt minimal gravitational decoupling scheme to extend a non-static spherically symmetric isotropic composition to anisotropic interior in \(f({\mathcal {R}},{\mathcal {T}},{\mathcal {R}}_{\textrm{ab}}{\mathcal {T}}^{\textrm{ab}})\) theory. A geometric deformation is applied only on \(g_{rr}\) metric component through which the modified field equations are separated into two sets, each of them correspond to their parent (seed and newly added) source. An isotropic model suggested by the Friedmann–Lemaitre–Robertson–Walker metric is adopted to reduce the unknowns in the first set. We then obtain an isotropic solution by making use of a linear equation of state and a particular form of the scale factor. A density-like constraint is chosen to solve the other sector containing the deformation function and multiple components of an additional matter source. Further, the graphical interpretation of the developed model is carried out to analyze how a decoupling parameter and modified gravity influence the evolutionary phases of the universe. It is concluded that only the radiation-dominated era meets stability criteria everywhere in this matter-geometry coupled theory.