We investigate the dynamical systems analysis of Friedmann–Robertson–Walker (FRW) cosmological model with wet dark fluid. A new equation of state for the dark energy component of the Universe has been used. It is modeled by the equation of state [Formula: see text], which can describe a liquid, e.g. water. To analyze the evolution equations, we have introduced suitable transformation of variables. The evolution of corresponding solutions is presented by curves in the phase–plane diagram. The nature of critical points are analyzed and stable attractors are examined for our cosmological model. We determine the classical stabilities of these cosmologies. We also examine the transition of early decelerating stage of the Universe to present the accelerating stage of the Universe.
We have presented FRW cosmological model in the framework of Brans-Dicke theory. This paper deals with a new proposed form of deceleration parameter and cosmological constant Λ. The effect of bulk viscosity is also studied in the presence of modified Chaplygin gas equation of state (p=Aρ-B/ρn). Furthermore, we have discussed the physical behaviours of the models.
The paper deals with the investigation of a homogeneous and anisotropic space-time described by Bianchi type-III metric with perfect fluid in Lyra geometry setting. Exact solutions of Einstein’s field equations have been obtained under the assumption of quadratic equation of state (EoS) of the form [Formula: see text], where [Formula: see text] is a constant and strictly [Formula: see text]. The physical and geometrical aspects are also examined in detail.
Exact solutions are obtained for an inhomogeneous cosmological model in normal gauge for Lyra's geometry. Some properties of the model have also been discussed.
In this paper, homothetic vector fields of a spatially homogenous Bianchi type-I cosmological model have been evaluated based on Lyra geometry. Further, we investigate the equation of state in cases when a displacement vector [Formula: see text] is a function of t and when it is constant. We give a comparison between the obtained results, using Lyra geometry, and those obtained previously in the context of general relativity, based on Riemannian geometry.
Bulk Viscous Cosmological Model in Brans-Dicke Theory with New Form of Time Varying Deceleration Parameter