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Related papers: Bulk Viscous Cosmological Models in General Relati…

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In a recent paper \cite{1}, we have studied the vacuum solutions of Bianchi types I and V spacetimes in the framework of metric f(R) gravity. Here we extend this work to perfect fluid solutions. For this purpose, we take stiff matter to…

General Relativity and Quantum Cosmology · Physics 2010-10-28 M. Sharif , M. Farasat Shamir

The study of a self-consistent system of interacting spinor and scalar fields within the scope of a Bianchi type I (BI) gravitational field in presence of a viscous fluid and $\Lambda$ term has been carried out. The system of equations…

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

In this paper, the crucial phenomenon of the expansion of the universe has been discussed. For this purpose, we study the vacuum solutions of Bianchi types $I$ and $V$ spacetimes in the framework of $f(R)$ gravity. In particular, we find…

General Relativity and Quantum Cosmology · Physics 2010-05-07 M. Sharif , M. Farasat Shamir

An LRS Bianchi-I space-time model is studied with constant Hubble parameter in $f(R,T)=R+2\lambda T$ gravity. Although a single (primary) matter source is considered, an additional matter appears due to the coupling between matter and…

General Relativity and Quantum Cosmology · Physics 2021-11-16 Vijay Singh , Aroonkumar Beesham

We investigate a new class of LRS Bianchi type-II cosmological models by revisiting in the paper of Mishra {\it et al} (2013) by considering a new deceleration parameter (DP) depending on the time in string cosmology for the modified…

General Physics · Physics 2021-08-02 Archana Dixit , Rashid Zia , Anirudh Pradhan

Bianchi type V string cosmological models with bulk viscosity for massive string are investigated. The bulk viscosity is assumed to vary with time in such a manner that it is related to simple power function of the energy density. Using…

General Relativity and Quantum Cosmology · Physics 2011-09-28 Anil Kumar Yadav

In this article, we have discussed the results of our investigation. We consider an anisotropic viscous cosmological model of (LRS) Bianchi type I spacetime universe filled with a viscous fluid under $f(Q)$ gravity. We have studied the…

General Relativity and Quantum Cosmology · Physics 2024-08-14 Anirudh Pradhan , Archana Dixit , Dinesh Chandra Maurya

Bianchi type V string cosmological models in general relativity are investigated. To get the exact solution of Einstein's field equations, we have taken some scale transformations followed by Camci $\it et ~ al$ (2001). It is shown that…

General Relativity and Quantum Cosmology · Physics 2011-06-07 Anil Kumar Yadav , Vineet Kumar Yadav , Lallan Yadav

Assuming conformally flat metric we obtain inhomogeneous solutions of Einstein equations with the energy-momentum of a viscous fluid. We suggest that the viscous solution can be applied as a model of an expanding inhomogeneous dark energy.

General Relativity and Quantum Cosmology · Physics 2020-03-31 Z. Haba

We investigate the out-of-equilibrium dynamics of viscous fluids in a spatially flat Friedmann-Lema\^itre-Robertson-Walker cosmology using the most general causal and stable viscous energy-momentum tensor defined at first order in spacetime…

General Relativity and Quantum Cosmology · Physics 2023-07-31 Fábio S. Bemfica , Marcelo M. Disconzi , Jorge Noronha , Robert J. Scherrer

We investigate the integrability of cosmic strings in Bianchi III space-time in presence of a bulk viscous fluid by applying a new technique. The behaviour of the model is reduced to the solution of a single second order nonlinear…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Mahesh Kumar Yadav , Anju Rai , Anirudh Pradhan

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

We have examined the cosmological solutions with variable G and $\lambda$ and bulk viscosity. It is found that these solutions are free from the cosmological problems of the Standard Model. The proposed cosmology consists of two arbitrary…

Astrophysics · Physics 2007-05-23 Arbab I. Arbab

Bulk viscosity leads to negative pressure, which is a key ingredient for successful inflation. We build an inflationary model where the slow-roll of the inflaton field is driven by a viscous component instead of the flat potential commonly…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Luca Visinelli

We study the homogeneous but anisotropic Bianchi type-V cosmological model with time-dependent gravitational and cosmological "constants". Exact solutions of the Einstein field equations (EFEs) are presented in terms of adjustable…

General Relativity and Quantum Cosmology · Physics 2018-07-30 Alnadhief H. A. Alfedeel , Amare Abebe , Hussam M. Gubara

In this article 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. The effect of bulk viscosity is also studied in…

General Relativity and Quantum Cosmology · Physics 2017-07-27 G. P. Singh , Binaya K. Bishi

The irrotational Bianchi V cosmological model under the influence of both shear and bulk viscosity, together with heat flux, has been studied. Exact solutions for the model are obtained with three physically viable assumptions. The first…

General Relativity and Quantum Cosmology · Physics 2019-12-09 A. Banerjee , Abhik Kumar Sanyal

We investigate whether viscous cold dark matter (vCDM) in a $\Lambda$-dominated FLRW universe can alleviate the Hubble tension while satisfying thermodynamic constraints, examining both flat and curved geometries. We model vCDM with bulk…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-29 R. Noemí Villalobos , Yerko Vásquez , Norman Cruz , Carlos H. López-Caraballo

Recent studies indicate that, near equilibrium condition could not be maintained for bulk viscous matter models during the accelerated expansion of the universe in the context of Einstein's gravity, without including the cosmological…

General Relativity and Quantum Cosmology · Physics 2023-03-28 Vishnu A Pai , Titus K Mathew

In a spatially flat Friedmann-Lema\^{i}tre-Robertson-Walker universe, we investigate a unified cosmic fluid scenario endowed with bulk viscosity in which the coefficient of the bulk viscosity has a power law evolution. The power law in the…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-20 Weiqiang Yang , Supriya Pan , Eleonora Di Valentino , Andronikos Paliathanasis , Jianbo Lu
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