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相关论文: The Dynamics of a Two-Fluid Bianchi Type I Univers…

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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

In this paper, we study a Bianchi type -I model of universe filled with barotropic and dark energy(DE) type fluids. The present values of cosmological parameters such as Hubble constant $H_0$, barotropic, DE and anisotropy energy parameters…

广义相对论与量子宇宙学 · 物理学 2021-08-03 G. K. Goswami , Meena Mishra , Anil Kumar Yadav , Anirudh Pradhan

Cosmological solutions are obtained in an anisotropic Kantowski-Sachs (KS) and Bianchi Type-I universes considering a cosmological constant with Skyrme fluid. Interestingly, the solutions obtained here in both the KS and Bianchi-I…

广义相对论与量子宇宙学 · 物理学 2022-06-09 Rikpratik Sengupta , B C Paul , Prasenjit Pal

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

The present paper deals with the dynamics of spatially flat Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmological model with a time varying cosmological constant $\Lambda$ where $\Lambda$ evolves with the cosmic time (t) through the…

广义相对论与量子宇宙学 · 物理学 2022-10-19 Chingtham Sonia , S. Surendra Singh

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

A systematic dynamical system approach is applied to study the cosmology of anisotropic Bianchi I universes in which a vector field is assumed to operate on a disformal frame. This study yields a number of new fixed points, among which…

宇宙学与河外天体物理 · 物理学 2015-09-02 Tomi S. Koivisto , Federico R. Urban

Spatially homogeneous but totally anisotropic and non-flat Bianchi type II cosmological model has been studied in general relativity in the presence of two minimally interacting fluids; a perfect fluid as the matter fluid and a hypothetical…

广义相对论与量子宇宙学 · 物理学 2012-06-18 Suresh Kumar , Ozgur Akarsu

In this paper we give, for the first time, a complete description of the dynamics of tilted spatially homogeneous cosmologies of Bianchi type II. The source is assumed to be a perfect fluid with equation of state $p = (\gamma -1) \mu$,…

广义相对论与量子宇宙学 · 物理学 2015-06-25 C. G. Hewitt , R. Bridson , J. Wainwright

We investigate diagonal Bianchi-I spacetimes in the presence of viscous fluids by using the shear and the anisotropic pressure components as the basic variables, where the viscosity is driven by the (second-order) causal thermodynamics. A…

广义相对论与量子宇宙学 · 物理学 2017-02-13 Eduardo Bittencourt , Leandro G. Gomes , Renato Klippert

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

The dynamics of a class of cosmological models with collisionless matter and four Killing vectors is studied in detail and compared with that of corresponding perfect fluid models. In many cases it is possible to identify asymptotic states…

广义相对论与量子宇宙学 · 物理学 2009-10-31 A. D. Rendall , K. P. Tod

In the present paper we discuss dynamic of anisotropic Bianchi I Universe filled by the perfect fluid in teleparallel $f(T)$-gravity. By using as analytical as numerical approaches we confirm the main results of previous authors such as…

广义相对论与量子宇宙学 · 物理学 2022-04-25 Petr V. Tretyakov

We perform the dynamical system analysis of the Locally Rotationally Symmetric (LRS) Bianchi type-I cosmological model in f(T) gravity in the presence of energy interaction . A cosmologically viable form of $f(T)$ is chosen (where $T$ is…

广义相对论与量子宇宙学 · 物理学 2025-10-14 Shivangi Rathore , S. Surendra Singh

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

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

A new class of LRS Bianchi type ${\rm VI}_{0}$ cosmological models with free gravitational fields and a variable cosmological term is investigated in presence of perfect fluid as well as bulk viscous fluid. To get the deterministic solution…

广义相对论与量子宇宙学 · 物理学 2012-04-13 Anirudh Pradhan , Shyam Sundar Kumhar , Padmini Yadav , Kanti Jotania

We use one of the simplest forms of the K-essence theory and we apply it to the classical anisotropic Bianchi type I cosmological model, with a barotropic perfect fluid modeling the usual matter content and with cosmological constant. The…

广义相对论与量子宇宙学 · 物理学 2014-09-11 J. Socorro , Luis O. Pimentel , Abraham Espinoza-García

In this paper, we investigate Bianchi type-$VI$ cosmological model for the universe filled with dark energy and viscous fluid in the presence of cosmological constant. Also, we show accelerating expansion of the universe by drawing volume…

广义相对论与量子宇宙学 · 物理学 2013-08-29 J. Sadeghi , Ali R. Amani , N. Tahmasbi

We present a dynamical analysis in terms of new expansion-normalized variables for homogeneous and anisotropic Bianchi-I spacetimes in $f(R)$ gravity in the presence of anisotropic matter. With a suitable choice of the evolution parameter,…

广义相对论与量子宇宙学 · 物理学 2019-03-29 Saikat Chakraborty , Kazuharu Bamba , Alberto Saa