Anisotropic models with generalized hybrid expansion in Brans–Dicke theory of gravity

Abstract

The hybrid expansion law (HEL) for average scale factor that yields power-law and exponential-law cosmologies is considered in spatially homogenous and anisotropic Bianchi type-I model in the context of Brans–Dicke (BD) Theory of gravitation. The solutions of the field equations have been calculated by assuming the power-law expression between the average scale factor [Formula: see text] and scalar field ([Formula: see text]). We studied both interacting and non-interacting forms of dark energy and dark matter and obtained respective solutions. The energy density [Formula: see text] decreases with time while energy densities [Formula: see text] increases with time. In both the cases, the physical acceptability and stability of the models are also studied. The coincidence problem in [Formula: see text]CDM model can be ruled out with proper choice of coupling between dark matter (DM) and dark energy (DE). We also discussed the physical behaviors of the derived models with the current observations applied to late-time acceleration and beginning of the universe. In this model, it is observed that our HEL Bianchi type I universe is highly anisotropic in the beginning of universe and becomes isotropic and overlaps with flat [Formula: see text]CDM model at late times.