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We study Bianchi cosmologies in the ghost-free bigravity theory assuming both metrics to be homogeneous and anisotropic, of the Bianchi class A, which includes types I,II,VI$_0$,VII$_0$,VIII, and IX. We assume the universe to contain a…

High Energy Physics - Theory · Physics 2013-11-08 Kei-ichi Maeda , Mikhail S. Volkov

In this article, we propose an anisotropic Bianchi-I type cosmological model in non-conservative Unimodular Gravity ($\mathrm{NUG}$). We show that simply using the Bianchi-I type metric does not resolve a striking characteristic of the…

General Relativity and Quantum Cosmology · Physics 2025-11-26 Marcelo H. Alvarenga , Júlio C. Fabris

The observational evidence regarding the present cosmological aspects tells us about the presence of very little anisotropy in the universe on a large scale. Here, in this paper, we attempt to study locally rotationally symmetric (LRS)…

General Relativity and Quantum Cosmology · Physics 2022-11-02 N. S. Kavya , V. Venkatesha , Sanjay Mandal , P. K. Sahoo

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

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 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 analyze the state space of a Bianchi-I universe with anisotropic sources. Here we consider an extended state space which includes null geodesics in this background. The evolution equations for all the state observables are derived.…

General Relativity and Quantum Cosmology · Physics 2016-02-09 Pavan K. Aluri , Sukanta Panda , Manabendra Sharma , Snigdha Thakur

We present an anisotropic cosmological model based on a new exact solution of Einstein equations. The matter content consists of an anisotropic scalar field minimally coupled to gravity and of two isotropic perfect fluids that represent…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Saulo Carneiro , Guillermo A. Mena Marugan

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

In this paper we investigate the past evolution of an anisotropic Bianchi I universe in $R+R^2$ gravity. Using the dynamical system approach we show that there exists a new two-parameters set of solutions that includes both an isotropic…

General Relativity and Quantum Cosmology · Physics 2018-05-09 Daniel Müller , Angelo Ricciardone , Alexei A. Starobinsky , Aleksey Toporensky

Within the framework of the local limit of nonlocal gravity (NLG), we investigate a class of Bianchi type I spatially homogeneous but anisotropic cosmological models. The modified field equations are presented in this case and some special…

General Relativity and Quantum Cosmology · Physics 2023-08-24 Javad Tabatabaei , Abdolali Banihashemi , Shant Baghram , Bahram Mashhoon

Despite having the somewhat successful description of accelerated cosmology, the early evolution of the universe always challenges mankind. Our promising approach lies in a new class of symmetric teleparallel theory of gravity named $f(Q)$,…

General Relativity and Quantum Cosmology · Physics 2022-01-25 Avik De , Sanjay Mandal , J. T. Beh , Tee-How Loo , P. K. Sahoo

We study the late-time evolution of an anisotropic Bianchi-I universe with radiation in the framework of asymptotically safe gravity. We first discuss the radiation-dominated universe for the perfect fluid with the equation of state…

General Relativity and Quantum Cosmology · Physics 2026-04-24 Chiang-Mei Chen , Ting-Kui Fan , Rituparna Mandal , Nobuyoshi Ohta

In this work, we conduct a noncommutative analysis of a Bianchi I model coupled to a reduced relativistic gas. The classical field equations are modified by introducing noncommutativity through a generalized symplectic formalism. We observe…

General Relativity and Quantum Cosmology · Physics 2025-05-13 Thiago Moralles de Abreu , Gil de Oliveira Neto , Albert Carlo Rodrigues Mendes , Simpliciano Castardelli dos Reis

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

The dynamics of cosmological models with isotropic matter sources (perfect fluids) is extensively studied in the literature; in comparison, the dynamics of cosmological models with anisotropic matter sources is not. In this paper we…

General Relativity and Quantum Cosmology · Physics 2011-02-16 Simone Calogero , J. Mark Heinzle

In this paper, we consider spatially homogenous and anisotropic Bianchi type I universe in the context of F(T) gravity. We construct some corresponding models using conservation equation and equation of state parameter representing…

General Relativity and Quantum Cosmology · Physics 2015-05-28 M. Sharif , Shamaila Rani

In this paper, the dynamical behavior of the anisotropic universe has been investigated in $f(R,T)$ theory of gravity. The functional $f(R,T)$ has been rescaled in the form $f(R,T)=\mu R+\mu T$, where $R$ is the Ricci scalar and $T$ is the…

General Physics · Physics 2018-01-08 B. Mishra , S Tarai , S. K. J. Pacif

In this paper, we investigate a non-canonical scalar field model in the background dynamics of anisotropic Locally Rotationally Symmetric (LRS) Bianchi type I universe where gravity is coupled minimally to scalar field which is taken as…

General Relativity and Quantum Cosmology · Physics 2023-11-17 Sujoy Bhanja , Goutam Mandal , Abdulla Al Mamon , Sujay Kr. Biswas

In this work, we investigate the cosmological dynamics of an anisotropic Universe within the framework of $f(R,T)$ gravity by incorporating pressureless dark matter and the dark energy models. The analysis is carried out in a Bianchi type-I…

General Relativity and Quantum Cosmology · Physics 2026-05-13 S. H. Shekh , N. Myrzakulov , Anirudh Pradhan , M. Zeyauddin
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