English
Related papers

Related papers: Bianchi Type III Anisotropic Dark Energy Models wi…

200 papers

Two variable $\Lambda$ models, viz. $\Lambda \sim (\dot a/a)^2$ and $\Lambda \sim \rho$ have been studied under the assumption that the equation of state parameter $\omega$ is a function of time. The selected $\Lambda$ models are found to…

General Relativity and Quantum Cosmology · Physics 2010-05-07 Utpal Mukhopadhyay , Saibal Ray , Farook Rahaman

We generalize the predictions for the CMB anisotropy patterns arising in Bianchi type VIIh universes to include a dark energy component. We consider these models in light of the result of Jaffe et al. (2005a,b) in which a correlation was…

Astrophysics · Physics 2009-11-13 T. R. Jaffe , S. Hervik , A. J. Banday , K. M. Gorski

An LRS Bianchi I model is considered with constant deceleration parameter, $q=\alpha-1$, where $\alpha\geq0$ is a constant. The physical and kinematical behaviour of the models for $\alpha=0$ and $\alpha\neq0$ is studied in detail. The…

General Relativity and Quantum Cosmology · Physics 2019-12-13 Vijay Singh , Aroonkumar Beesham

We investigate the anisotropic parameterization of the dark energy equation of state within the framework of an axisymmetric (planar) Bianchi-I universe. Using the latest Pantheon+ Type Ia Supernova dataset, augmented by SH0ES Cepheid…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Anshul Verma , Pavan K. Aluri , David F. Mota

This manuscript investigate the dark energy Bianchi type-I cosmological models in presence of generalized Chaplygin gas, variable gravitational and cosmological constants. In this manuscript, exact solutions of Einstein field equations are…

General Relativity and Quantum Cosmology · Physics 2022-02-11 N. Hulke , G. P. Singh , Binaya K Bishi

We investigate some new similarity inhomogeneous solutions of anisotropic dark energy and perfect fluid in Bianchi type-I space-time. Three different equation of state parameters along the spatial directions are introduced to quantify the…

General Relativity and Quantum Cosmology · Physics 2018-04-12 Ahmad T Ali , Anil Kumar Yadav , Abdulah K Alzahrani

Anisotropic dark energy model with dynamic pressure anisotropies along different spatial directions is constructed at the backdrop of a spatially homogeneous diagonal Bianchi type $V$ $(BV)$ space-time in the framework of General…

General Physics · Physics 2017-05-10 B. Mishra , S. K. Tripathy

In this paper, spatially homogeneous and anisotropic Bianchi type-I cosmological models of Brans-Dicke theory of gravitation are investigated. The model represents accelerating universe at present and is considered to be dominated by dark…

General Physics · Physics 2021-08-02 Umesh Kumar Sharma , Gopi Kant Goswami , Anirudh Pradhan

In this paper, we constrain dark energy models using a compendium of observations at low redshifts. We consider the dark energy as a barotropic fluid, with the equation of state a constant as well the case where dark energy equation of…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-21 Ashutosh Tripathi , Archana Sangwan , H. K. Jassal

In this work, we study a cosmological model of Bianchi type-I Universe in teleparallel gravity for a perfect fluid. To obtain the cosmological solution of the model, we assume that the deceleration parameter is a linear function of the…

General Relativity and Quantum Cosmology · Physics 2022-05-25 M. Koussour , M. Bennai

The present study deals with spatially homogeneous and anisotropic Bianchi-I cosmological model representing massive strings. The energy-momentum tensor, as formulated by Letelier (Phys. Rev. D 28: 2414, 1983) has been used to construct…

General Physics · Physics 2014-03-11 Chanchal Chawla , R. K. Mishra , Anirudh Pradhan

This manuscript presents a diagnostic analysis of three dark energy models resulting from the parametrization of the deceleration parameter. These models exhibit intriguing features, including late-time acceleration and a cosmological phase…

General Relativity and Quantum Cosmology · Physics 2024-08-12 Dhruv Arora , Himanshu Chaudhary , Shibesh Kumar Jas Pacif , G. Mustafa

We study Bianchi type $I$ cosmological model in the presence of magnetized anisotropic dark energy. The energy-momentum tensor consists of anisotropic fluid with anisotropic EoS $p=\omega{\rho}$ and a uniform magnetic field of energy…

General Relativity and Quantum Cosmology · Physics 2010-11-03 M. Sharif , M. Zubair

Spatially homogeneous but totally anisotropic and non-flat Bianchi type II cosmological model has been studied in general relativity in the presence of two minimally interacting fluids; a perfect fluid as the matter fluid and a hypothetical…

General Relativity and Quantum Cosmology · Physics 2012-06-18 Suresh Kumar , Ozgur Akarsu

The main purpose of the present paper is to investigate LRS Bianchi type I metric in the presence of perfect fluid and dark energy. In order to obtain a deterministic solution of the field equations we have assumed that, the two sources of…

General Relativity and Quantum Cosmology · Physics 2020-03-06 Y. S. Solanke , D. D. Pawar , V. J. Dagwal

The present study deals with spatially homogeneous and anisotropic locally rotationally symmetric (LRS) Bianchi type I cosmological model with dominance of dark energy. To get the deterministic model of Universe, we assume that the shear…

General Physics · Physics 2012-01-24 Anil Kumar Yadav , Bijan Saha

Tensions in late-time expansion data have renewed interest in models beyond $\Lambda$CDM. We ask: \emph{how isotropic must dark energy be?} Working in Bianchi~I, we allow time-dependent anisotropic stress and introduce a parameterisation…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-02 Richard A. Battye , Adam Moss

The Bianchi type-I universe filled with dark energy from a wet dark fluid has been considered. A new equation of state for the dark energy component of the universe has been used. It is modeled on the equation of state $p=\gamma (\rho…

General Relativity and Quantum Cosmology · Physics 2014-11-21 T. Singh , R. Chaubey

We investigate the effect of dark energy on the limits on the shear anisotropy in spatially homogeneous Bianchi cosmological models obtained from measurements of the temperature anisotropies in the cosmic microwave background. We shall…

Astrophysics · Physics 2010-05-12 A. A. Coley , W. C. Lim

Spatially homogeneous and anisotropic Bianchi type $VI_0$ cosmological models with cosmological constant are investigated in the presence of anisotropic dark energy. We examine the effects of electromagnetic field on the dynamics of the…

General Relativity and Quantum Cosmology · Physics 2010-11-24 M. Sharif , M. Zubair