Anisotropic Dark Energy Cosmological Models Research Articles

Anisotropic Bianchi Type-1 Cosmological Model Containing Dark Energy

Considering the LRS Bianchi type I metric here we studied the spatial homogeneous and anisotropic dark energy cosmological models in the frame work of B-D scalar tensor theory of gravity along with variable equation of parameter and deceleration parameter. Exact solutions of field equations are obtained with certain physical assumptions in different cases. The physical behavior of the model is also discussed in details.

Magnetized Anisotropic Dark Energy Cosmological Model in f(R) Gravity Theory Using Special Law of Variation

Magnetized Anisotropic Dark Energy Cosmological Model in f(R) Gravity Theory Using Special Law of Variation

Dynamics of Bianchi type-$$\hbox {VI}_{0}$$ anisotropic dark energy cosmological model with massive scalar field in Lyra manifold

Dynamics of Bianchi type-$$\hbox {VI}_{0}$$ anisotropic dark energy cosmological model with massive scalar field in Lyra manifold

Anisotropic dark energy cosmological model with cosmic strings

This study deals with a spatially homogeneous locally rotationally symmetric Bianchi type-I dark energy cosmological model containing a one-dimensional cosmic string fluid source. Einstein’s field equations are solved by using a relation between the metric potentials and hybrid expansion law of the average scale factor. We discuss the accelerated expansion of our model through the equation of state (EOS; ωde) and deceleration parameter (q). We observe that in the evolution of our model, the EOS parameter starts from matter-dominated phase ωde > −1/3 and ultimately attains a constant value in the quintessence region (−1 < ωde < −1/3). The EOS parameter of the model never crosses the phantom divide line (ωde = −1). These facts are consistent with recent observations. We also discuss some other physical parameters.

Kaluza-Klein dark energy model in Lyra manifold in the presence of massive scalar field

In this investigation we intend to study the dynamics of an anisotropic dark energy cosmological model in the presence of a massive scalar field in a modified Riemannian manifold proposed by Lyra (Math. Z. 54:52, 1951) in the background of a five dimensional Kaluza-Klein space time. We solve the Einstein field equations using some physically significant conditions and present a deterministic dark energy cosmological model. We use here the time dependent displacement vector field of the Lyra manifold. All the dynamical parameters of the model, namely, average Hubble parameter, anisotropy parameter, equation of state parameter, dark energy density, deceleration parameter and statefinders are evaluated for our model and their physical relevance to modern cosmology is discussed in detail.

Dynamics of anisotropic dark energy universe embedded in one-directional magnetized fluid

In this work, we have constructed an anisotropic dark energy cosmological model in a two-fluid situation, such as the usual dark energy and the magnetized fluid. We have assumed the dark energy pressure to be anisotropic in different spatial directions. In order to develop the mathematical formalism of the model, we have considered the scale factor as hybrid scale factor which is a combination of both power law and exponential volumetric expansion law. The physical parameters are derived and analyzed and found to be in agreement with the observational limits.

Five-Dimensional anisotropic Dark energy Cosmological model in the presence of Scalar-Meson fields in General relativity

Five-Dimensional anisotropic Dark energy Cosmological model in the presence of Scalar-Meson fields in General relativity

Dynamical Anisotropic Dark Energy Cosmological Model in General Relativity

ABSTRACTWe have investigated an anisotropic dark energy cosmological model in the presence of anisotropic dark energy fluid coupled with mass less scalar field in KantowskiSachs space-time in general theory of relativity. A physically viable dark energy cosmological model is presented using (i) a hybrid expansion law proposed by Akarsu et al. (JCAP. 01, 022: 2014) and (ii) a relation between the metric potential. The dark energy density, the equation of state (EoS) parameter and the skewness parameters of the model are determined and their physical siguificance is pointed out. The deceleration parameter and the jerk parameter of the model show that there is a smooth transition of the uuiverse from early deceleration to late time acceleration which confirms the observations modem cosmology.

Dynamics of Bianchi type-V anisotropic dark energy cosmological model in a scale covariant theory of gravitation

This paper is devoted to the discussion of dynamical properties of anisotropic dark energy cosmological model of the universe in a Bianchi type-V space time in the framework of scale covariant theory of gravitation formulated by Canuto et al.(phys.Rev.Lett.39:429,1977).A dark energy cosmological model is presented by solving the field equations of this theory by using some physically viable conditions. The dynamics of the model is studied by computing the cosmological parameters, dark energy density, equation of state(EoS) parameter, skewness parameters, deceleration parameter and the jerk parameter. This being a scalar field model gives us the quintessence model of the universe which describes a significant dark energy candidate of our accelerating universe. All the physical quantities discussed are in agreement with the recent cosmological observations.

Anisotropic Cosmological Models with Two Fluids

Anisotropic dark energy cosmological models have been constructed in a Bianchi V space-time, with the energy momentum tensor consisting of two noninteracting fluids, namely, bulk viscous fluid and dark energy fluid. Two different models are constructed based on the power law cosmology and de Sitter universe. The constructed model was also embedded with different pressure gradients along different spatial directions. The variable equation of state (EoS) parameter and skewness parameters for both models are obtained and analysed. The physical properties of the models obtained with the use of scale factors of power law and de Sitter law are also presented.

Unified dark fluid in Brans–Dicke theory

Anisotropic dark energy cosmological models are constructed in the frame work of generalised Brans-Dicke theory with a self interacting potential. Wet dark fluid characterized by a linear equation of state is considered as the source of dark energy. Shear scalar is considered to be proportional to the expansion scalar simulating an anisotropic relationship among the directional expansion rates. The dynamics of the universe in presence of wet dark fluid in anisotropic background have been discussed. The presence of evolving scalar field makes it possible to get accelerating phase of expansion even for a linear relationship among the directional Hubble rates. It is found that, the anisotropy in expansion rates does not affect the scalar field, self interacting potential but it controls the non-evolving part of the Brans- Dicke parameter.

Magnetized anisotropic dark energy cosmological models in scale covariant theory of gravitation

In the present paper, we have investigated Bianchi type II, VIII and IX spacetime in the presence of magnetized anisotropic dark energy in the Scale covariant theory of gravitation. Exact solution of the field equations are obtained by assuming the expansion anisotropy (the ratio of shear scalar to expansion scalar) to be a function of average scale factor. The isotropy of the fluid, space and expansion are examined.

The Measurement of and in Bianchi Type-I Anisotropic Dark Energy Cosmological Model with Constant Deceleration Parameter in Bimetric Theory of Gravitation

The Measurement of and in Bianchi Type-I Anisotropic Dark Energy Cosmological Model with Constant Deceleration Parameter in Bimetric Theory of Gravitation