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The field equations of Brans-Dicke gravity coupled to a mass-varying vector field are derived. Anisotropic cosmological solutions with a locally rotationally symmetric Bianchi type I metric and time-dependent scalar and electric vector…

General Relativity and Quantum Cosmology · Physics 2014-02-05 Ozgur Akarsu , Tekin Dereli , Neslihan Oflaz

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 consider the Bianchi type-I space-time with perfect fluid as matter content of the Universe in the framework of $f(Q)$ gravity (where $% Q$ is the non-metricity scalar) recently proposed by Jim\'{e}nez et al. (Phys. Rev. D…

General Relativity and Quantum Cosmology · Physics 2022-08-18 M. Koussour , S. H. Shekh , M. Bennai

We study the dynamics of the Bianchi~I cosmological model in the presence of both polymer quantization effects and an exponential deformation of the Poisson algebra. Starting from the Hamiltonian formulation, we derive the polymer-deformed…

General Relativity and Quantum Cosmology · Physics 2025-10-09 Babak Vakili

A new class of exact solutions of Einstein's field equations with perfect fluid for an LRS Bianchi type-I spacetime is obtained by using a time dependent deceleration parameter. We have obtained a general solution of the field equations…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Anirudh Pradhan , S. Otarod

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

The objective of this work enclosed with the study of spatially homogeneous anisotropic Bianchi type-I universe in $f(R,T)$ gravity (where $R$ is the Ricci scalar and $T$ is the trace of stress energy momentum tensor) in two different cases…

General Relativity and Quantum Cosmology · Physics 2017-03-20 P. K. Sahoo , Parbati Sahoo , Binaya K. Bishi

The anisotropic Bianchi type I in multi-scalar field cosmology is studied with a particular potential of the form $\rm V= V_0 e^{-\left[\lambda_1 \phi_1 + \cdots + \lambda_n \phi_n \right]}\,,$ which emerges as a condition between the time…

General Relativity and Quantum Cosmology · Physics 2019-04-02 j. Socorro , Omar E. Núñez , Rafael Hernández-Jiménez

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 approach of a quantum state to a cosmological singularity is studied through the evolution of its moments in a simple version of a Bianchi I model. In spite of the simplicity, the model exhibits several instructive and unexpected…

General Relativity and Quantum Cosmology · Physics 2020-06-03 Ana Alonso-Serrano , Martin Bojowald , David Brizuela

We give the equations governing the shear evolution in Bianchi spacetimes for general f(R)-theories of gravity. We consider the case of R^n-gravity and perform a detailed analysis of the dynamics in Bianchi I cosmologies which exhibit local…

General Relativity and Quantum Cosmology · Physics 2010-11-05 Jannie A Leach , Sante Carloni , Peter K S Dunsby

Making use of the $1 + 3$ covariant formalism, we show explicitly the effect that nonmetricity has on the dynamics of the universe. Then, using the Dynamical System Approach, we analyze the evolution of Bianchi type-I cosmologies within the…

General Relativity and Quantum Cosmology · Physics 2022-11-16 Fabrizio Esposito , Sante Carloni , Stefano Vignolo

This paper is devoted to investigate the exact solutions of Bianchi type $I$ spacetime in the context of $f(R,T)$ gravity [1], where $f(R,T)$ is an arbitrary function of Ricci scalar $R$ and trace of the energy momentum tensor $T$. For this…

General Relativity and Quantum Cosmology · Physics 2015-06-30 M. Farasat Shamir

The paper deals with a spatially homogeneous and anisotropic universe filled with perfect fluid and dark energy components. The two sources are assumed to interact minimally together with a special law of variation for the average Hubble's…

General Physics · Physics 2014-08-27 Suresh Kumar , Anil Kumar Yadav

The main purpose of this paper is to explore the solutions of Bianchi type $III$ cosmological model in Brans Dicke theory of gravity in the background of anisotropic dark energy. We use the assumption of constant deceleration parameter and…

General Relativity and Quantum Cosmology · Physics 2017-08-23 M. Farasat Shamir , Akhlaq Ahmad Bhatti

Considering the Universe as a dynamic system, the understanding of its evolution is an interesting aspect of study in cosmology. Here, we investigate the anisotropic locally rotationally symmetric (LRS) Bianchi type-I (LRS-BI) spacetime…

General Relativity and Quantum Cosmology · Physics 2024-06-21 Pranjal Sarmah , Umananda Dev Goswami

Expansion of a locally equilibrated fluid is considered in an anisotropic space-time given by Bianchi type I metric. Starting from isotropic equilibrium phase-space distribution function in the local rest frame, we obtain expressions for…

General Relativity and Quantum Cosmology · Physics 2018-05-08 Ashutosh Dash , Amaresh Jaiswal

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

We study the `initial state' of an anisotropic universe in Eddington-inspired Born-Infeld gravity filled with a scalar field, whose potential has various forms. With this purpose, the evolution of a spatially-flat, homogeneous anisotropic…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Hyeong-Chan Kim

We derived equations of motion corresponding to Bianchi-I cosmological models in the Lovelock gravity. Equations derived in the general case, without any specific ansatz for any number of spatial dimensions and any order of the Lovelock…

General Relativity and Quantum Cosmology · Physics 2010-01-22 S. A. Pavluchenko