中文
相关论文

相关论文: Cosmic anisotropy with Reduced Relativistic Gas

200 篇论文

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…

高能物理 - 理论 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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)…

广义相对论与量子宇宙学 · 物理学 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…

综合物理 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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.…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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 $f(Q)$,…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

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…

综合物理 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

综合物理 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 2026-05-13 S. H. Shekh , N. Myrzakulov , Anirudh Pradhan , M. Zeyauddin
‹ 上一页 1 2 3 10 下一页 ›