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Related papers: Anisotropic f(Q) gravity model with bulk viscosity

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We study the dynamical evolution of an $f(R)$ model of gravity in a viscous and anisotropic background which is given by a Bianchi type-I model of the Universe. We find viable forms of $f(R)$ gravity in which one is exactly the Einsteinian…

General Physics · Physics 2014-01-20 Kh. Saaidi , A. Aghamohammadi , H. Hossienkhani

In this study, we investigate the role of bulk viscosity in $f(Q,T)$ gravity in explaining late-time cosmic acceleration. This model, an extension of symmetric teleparallel gravity, introduces viscosity into cosmic matter dynamics for a…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-14 M. Koussour , Abdelghani Errehymy , O. Donmez , K. Myrzakulov , M. A. Khan , B. Çil , E. Güdekli

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

We investigated a bulk viscous fluid universe with cosmological constant {\Lambda} by assuming that the bulk viscosity to be proportional to the Hubble parameter. We found that for an expanding universe, the (relative) matter density will…

General Relativity and Quantum Cosmology · Physics 2024-01-25 Jinwen Hu , Huan Hu

With the non-metricity scalar $Q$ as the functional argument, several $f(Q)$ gravity models are found to be proposed which are perfectly able to mimic the late-time accelerated expansion as pointed out by the type Ia supernovae…

General Relativity and Quantum Cosmology · Physics 2026-02-03 Subhajit Pal , Atanu Mukherjee , Ritabrata Biswas , Farook Rahaman

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

In this paper, we present a cosmological model within the framework of symmetric teleparallel gravity, focusing on $f(Q)$ gravity, where $Q$ represents the non-metricity scalar. Utilizing cosmological datasets, we derive an accelerating…

General Relativity and Quantum Cosmology · Physics 2024-08-09 S. A. Narawade , S. H. Shekh , B. Mishra , Wompherdeiki Khyllep , Jibitesh Dutta

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

An analysis is presented of the Bianchi type I cosmological models with a bulk viscosity when the universe is filled with the stiff fluid $p = \epsilon$ while the viscosity is a power function of the energy density, such as $\eta = \alpha…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Wung-Hong Huang

In this paper, we discuss the phase space analysis of locally rotationally symmetric Bianchi type I universe model by taking a noninteracting mixture of dust like and viscous radiation like fluid whose viscous pressure satisfies a nonlinear…

General Relativity and Quantum Cosmology · Physics 2019-05-29 M. Sharif , Saadia Mumtaz

$f(Q,T)$ theory of gravity is very recently proposed to incorporate within the action Lagrangian, the trace $T$ of the energy-momentum tensor along with the non-metricity scalar $Q$. The cosmological application of this theory in a…

General Relativity and Quantum Cosmology · Physics 2023-05-24 Tee-How Loo , M. Koussour , Avik De

In this paper, we have investigated an anisotropic cosmological model in $f(Q)$ gravity with string fluid in LRS Bianchi type-I universe. We have considered the arbitrary function $f(Q)=Q+\alpha\sqrt{~Q}+2\Lambda$ where $\alpha$ is model…

General Relativity and Quantum Cosmology · Physics 2023-03-02 Dinesh Chandra Maurya , Archana Dixit , Anirudh Pradhan

We investigate the late-time cosmic acceleration within the framework of viscous $f(T,L_m)$ gravity, where the gravitational action depends on both the torsion scalar $T$ and the matter Lagrangian $L_m$. In this context, the Universe is…

General Physics · Physics 2026-03-24 M. Koussour , Alnadhief H. A. Alfedeel , S. Muminov , J. Rayimbaev

Anisotropic Bianchi type-III cosmology is examined within the framework of f(R,T) gravity, where R denotes the Ricci scalar and T the trace of the energy-momentum tensor. In this work, we investigate the statistical constraints on…

General Relativity and Quantum Cosmology · Physics 2025-12-23 Mayur Mune , Praveen Kumar Dhankar , Safiqul Islam , Behnam Pourhassan , Muhammad Aamir , Faisal Haroon

We study a warm inflationary model for different expansions assuming an anisotropic universe described by Bianchi I metric. The universe is filled with a scalar field or inflaton, radiation, and bulk viscous pressure. We carry out the…

General Relativity and Quantum Cosmology · Physics 2022-02-07 Mehdi Shokri , Jafar Sadeghi , Ramón Herrera , Saeed Noori Gashti

In this study, we have demonstrated the expansion history of an axially symmetric Bianchi type-I model of the universe. Our model as of now presents an accelerating universe, which had been in the decelerating phase in the past. Roles of…

General Relativity and Quantum Cosmology · Physics 2022-11-30 Vinod Kumar Bhardwaj , Archana Dixit , Rita Rani , G. K. Goswami , Anirudh Pradhan

The behaviour of magnetic field in anisotropic Bianchi type I cosmological model for bulk viscous distribution is investigated. The distribution consists of an electrically neutral viscous fluid with an infinite electrical conductivity. It…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Anirudh Pradhan , Sanjay Kumar Singh

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

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

A spatially homogeneous and locally rotationally symmetric Bianchi type-II cosmological model under the influence of both shear and bulk viscosity has been studied. Exact solutions are obtained with a barotropic equation of state between…

General Relativity and Quantum Cosmology · Physics 2021-05-11 A. Banerjee , S. B. Duttachoudhury , Abhik Kumar Sanyal