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相关论文: L.R.S. Bianchi type II Stiff Fluid cosmological mo…

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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…

广义相对论与量子宇宙学 · 物理学 2022-11-30 Vinod Kumar Bhardwaj , Archana Dixit , Rita Rani , G. K. Goswami , Anirudh Pradhan

We investigate a new class of LRS Bianchi type-II cosmological models by revisiting in the paper of Mishra {\it et al} (2013) by considering a new deceleration parameter (DP) depending on the time in string cosmology for the modified…

综合物理 · 物理学 2021-08-02 Archana Dixit , Rashid Zia , Anirudh Pradhan

It is investigated the behaviour of the ``constants'' $G,$ $c$ and $\Lambda $ in the framework of a perfect fluid LRS Bianchi I cosmological model. It has been taken into account the effects of a $c-$variable into the curvature tensor. Two…

广义相对论与量子宇宙学 · 物理学 2016-08-16 J. A. Belinchón

This study investigates the dynamics of a spatially homogeneous and anisotropic LRS Bianchi type-I universe with viscous fluid in the framework of $f(Q)$ symmetric teleparallel gravity. We assume a linear form for $f(Q)$ and introduce…

广义相对论与量子宇宙学 · 物理学 2024-04-16 M. Koussour , S. H. Shekh , M. Bennai , N. Myrzakulov

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…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Anirudh Pradhan , S. Otarod

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…

广义相对论与量子宇宙学 · 物理学 2015-05-01 Bijan Saha

Locally-rotationally-symmetric Bianchi type-I viscous and non -viscous cosmological models are explored in general relativity (GR) and in f(R,T) gravity. Solutions are obtained by assuming that the expansion scalar is proportional to the…

广义相对论与量子宇宙学 · 物理学 2021-07-07 S. Jokweni , Vijay Singh , Aroonkumar Beesham

We consider a self-consistent system of Bianchi type-I (BI) gravitational field and a binary mixture of perfect fluid and dark energy given by a cosmological constant. The perfect fluid is chosen to be the one obeying either the usual…

广义相对论与量子宇宙学 · 物理学 2015-05-01 Bijan Saha

We study a perfect fluid Bianchi II models with time varying constants under the self-similarity approach. In the first of the studied model, we consider that only vary $G$ and $\Lambda.$ The obtained solution is more general that the…

广义相对论与量子宇宙学 · 物理学 2009-08-11 José Antonio Belinchón

Within the scope of an anisotropic Bianchi type-VI cosmological model we have studied the evolution of the universe filled with perfect fluid and dark energy. To get the deterministic model of Universe, we assume that the shear scalar…

广义相对论与量子宇宙学 · 物理学 2015-05-01 Bijan Saha

An LRS Bianchi I model is considered with constant deceleration parameter, $q=\alpha-1$, where $\alpha\geq0$ is a constant. The physical and kinematical behaviour of the models for $\alpha=0$ and $\alpha\neq0$ is studied in detail. The…

广义相对论与量子宇宙学 · 物理学 2019-12-13 Vijay Singh , Aroonkumar Beesham

We numerically investigate the solutions to the effective equations of the Bianchi II model within the "improved" Loop Quantum Cosmology (LQC) dynamics. The matter source is a massless scalar field. We perform a systematic study of the…

广义相对论与量子宇宙学 · 物理学 2012-10-08 Alejandro Corichi , Edison Montoya

This paper is devoted to investigate the anisotropic locally rotationally symmetric (LRS) Bianchi type-I space-time in the context of the recently proposed $f(Q)$ gravity in which $Q$ is the non-metricity scalar. For this purpose, we…

广义相对论与量子宇宙学 · 物理学 2022-08-26 M. Koussour , K. El Bourakadi , S. H. Shekh , S. K. J. Pacif , M. Bennai

Bianchi type V matter filled universe with varying lambda in general relativity are investigated by using the law of variation for the generalized mean Hubble parameter. This yields the constant value of deceleration parameter and generates…

广义相对论与量子宇宙学 · 物理学 2013-01-15 Anil Kumar Yadav

The Bianchi type-I universe filled with dark energy from a wet dark fluid has been considered. A new equation of state for the dark energy component of the universe has been used. It is modeled on the equation of state $p=\gamma (\rho…

广义相对论与量子宇宙学 · 物理学 2014-11-21 T. Singh , R. Chaubey

Following the recent recognition of a positive value for the vacuum energy density and the realization that a simple Kantowski-Sachs model might fit the classical tests of cosmology, we study the qualitative behavior of three anisotropic…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Paulo Aguiar , Paulo Crawford

In this paper, we investigate Bianchi type$-V$ cosmological models with bulk viscous fluid and time varying cosmological $\Lambda$ and Newtonian $G$ parameters. The Einstein's field equations have been transformed into a coupling…

The present study deals with a spatially homogeneous and anisotropic Bianchi-II cosmological models representing massive strings in normal gauge for Lyra's manifold by applying the variation law for generalized Hubble's parameter that…

综合物理 · 物理学 2012-04-13 Shilpi Agarwal , R. K. Pandey , Anirudh Pradhan

We present the classical solutions to the Einstein field equations derived using the WKB-like and Hamilton procedures. The investigation is carried out in the commutative and noncommutative scenario for the Bianchi type I cosmological model…

广义相对论与量子宇宙学 · 物理学 2009-11-13 C. Ortiz , E. Mena-Barboza , M. Sabido , J. Socorro

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