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Related papers: Perturbations in Bianchi Type-I spacetimes with va…

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In this paper, we investigate Bianchi type$-V$ cosmological models with bulk viscous fluid and time varying cosmological $\Lambda$ and Newtonian $G$ parameters. The Einstein's field equations have been transformed into a coupling…

We study the growth of perturbations in an expanding Bianchi type-I metric that evolves according to an energy density that includes dust and a cosmological constant. Assuming an epoch where the cosmological constant is subdominant, we find…

High Energy Physics - Theory · Physics 2010-02-03 E. Dimastrogiovanni , W. Fischler , S. Paban

We study the evolution of a homogeneous, anisotropic Universe given by a Bianchi type-I cosmological model filled with viscous fluid, in the presence of a cosmological constant $\Lambda$. The role of viscous fluid and $\Lambda$ term in the…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha

In this paper we study the evolution of spatially homogeneous and anisotropic Bianchi type-I Universe models with the cosmological constant, \Lambda, and filled with nonlinear viscous fluid. The dynamical equations for these models are…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Nouraddin Mostafapoor , Oyvind Gron

In this paper we study the evolution of a LRS Bianchi I Universe, filled with a bulk viscous cosmological fluid in the presence of time varying constants "but" taking into account the effects of a c-variable into the curvature tensor. We…

General Relativity and Quantum Cosmology · Physics 2009-11-10 J. A. Belinchón

Bianchi type V viscous fluid cosmological model for barotropic fluid distribution with varying cosmological term $\Lambda$ is investigated. We have examined a cosmological scenario proposing a variation law for Hubble parameter $H$ in the…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Raj Bali , Pratibha Singh , J. P. Singh

Bianchi I cosmological models consisting of a fluid with both bulk and shear viscosity are studied. It is shown how the dynamical importance of the shear and the fluid density change in the course of evolution. Exact solutions with an…

General Relativity and Quantum Cosmology · Physics 2021-03-15 A. Banerjee , S. B. Duttachoudhury , Abhik Kumar Sanyal

The nature of cosmological solutions for a homogeneous, anisotropic Universe given by a Bianchi type-I (BI) model in the presence of a Cosmological constant $\Lambda$ is investigated by taking into account dissipative process due to…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha , V. Rikhvitsky

In this paper we have investigated an LRS Bianchi I anisotropic cosmological model of the universe by taking time varying $G$ and $\Lambda$ in the presence of bulk viscous fluid source described by full causal non-equilibrium…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Anirudh Pradhan , Purnima Pandey , G. P. Singh , R. V. Deshpandey

The standard cosmological model is challenged by an ever-growing collection of observations, which invites (and stimulates) inquiry into possible additions and/or alterations. One such alteration comes from letting cosmic isotropy -- as…

General Relativity and Quantum Cosmology · Physics 2026-04-22 Robbert W. Scholtens , Marcello Seri , Holger Waalkens , Rien van de Weygaert

In this paper we are to study homogeneous and anisotropic Bianchi type-V universe in presence of bulk viscous fluid source of matter with time function gravitational constant G and cosmological term lambda. The viscosity coefficient is…

General Relativity and Quantum Cosmology · Physics 2023-05-19 Nawsad Ali

We consider the dynamics of a causal bulk viscous cosmological fluid filled constantly decelerating Bianchi type I space-time. The matter component of the Universe is assumed to satisfy a linear barotropic equation of state and the state…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. K. Mak , T. Harko

We consider a Bianchi type-I Polytropic bulk viscous fluid cosmological model with variable G and {\Lambda}. To get a deterministic model, we assume some conditions of A, B, C, and polytropic relation to find the results. physical…

General Physics · Physics 2014-03-11 Rishi Kumar Tiwari , Mukesh Sharma , Sonia Sharma

Einstein's field equations with variable gravitational and cosmological ``constant'' are considered in presence of perfect fluid for Bianchi type-I spacetime. Consequences of the four cases of the phenomenological decay of $\Lambda$ have…

General Relativity and Quantum Cosmology · Physics 2008-11-26 J. P. Singh , A. Pradhan , A. K. Singh

Bianchi type I magnetized cosmological models in the presence of a bulk viscous fluid are investigated. The source of the magnetic field is due to an electric current produced along x-axis. The distribution consists of an electrically…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Anirudh Pradhan , Om Prakash Pandey

The present study deals with spatially homogeneous and totally anisotropic locally rotationally symmetric (LRS) Bianchi type I cosmological model with variable $G$ and $\Lambda$ in presence of imperfect fluid. To get the deterministic model…

General Physics · Physics 2012-01-17 Anil Kumar Yadav , Anirudh Pradhan , Ajay Kumar Singh

We consider the dynamics of a barotropic cosmological fluid in an anisotropic, Bianchi type I space-time in Eddington-inspired Born-Infeld (EiBI) gravity. By assuming an isotropic pressure distribution, we obtain the general solution of the…

General Relativity and Quantum Cosmology · Physics 2014-10-30 Tiberiu Harko , Francisco S. N. Lobo , M. K. Mak

We investigate diagonal Bianchi-I spacetimes in the presence of viscous fluids by using the shear and the anisotropic pressure components as the basic variables, where the viscosity is driven by the (second-order) causal thermodynamics. A…

General Relativity and Quantum Cosmology · Physics 2017-02-13 Eduardo Bittencourt , Leandro G. Gomes , Renato Klippert

Conformally flat tilted Bianchi type V cosmological models in presence of a bulk viscous fluid and heat flow are investigated. The coefficient of bulk viscosity is assumed to be a power function of mass density. The cosmological constant is…

General Relativity and Quantum Cosmology · Physics 2008-07-30 Anirudh Pradhan , S. K. Srivastav

Some Bianchi type I viscous fluid cosmological models with a variable cosmological constant are investigated in which the expansion is considered only in two direction i.e. one of the Hubble parameter $(H_{1} = \frac{A_{4}}{A})$ is zero.…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Anirudh Pradhan , Purnima Pandey
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