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

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We study Bianchi type $I$ cosmological model in the presence of magnetized anisotropic dark energy. The energy-momentum tensor consists of anisotropic fluid with anisotropic EoS $p=\omega{\rho}$ and a uniform magnetic field of energy…

广义相对论与量子宇宙学 · 物理学 2010-11-03 M. Sharif , M. Zubair

Stability, dark energy (DE) parameterization and swampland aspects for the Bianchi form-$VI_{h}$ universe have been formulated in an extended gravity hypothesis. Here we have assumed a minimally coupled geometry field with a rescaled…

综合物理 · 物理学 2021-08-03 Archana Dixit , Anirudh Pradhan

Bianchi type I cosmological models are studied that contain a stiff fluid with a shear viscosity that is a power function of the energy density, such as $\zeta = \alpha \epsilon^n$. These models are analyzed by describing the cosmological…

广义相对论与量子宇宙学 · 物理学 2016-08-31 Wung-Hong Huang

We consider a Bianchi type-I Polytropic bulk viscous fluid cosmological model with variable G and {\Lambda}. To get a deterministic model, we assume some conditions of A, B, C, and polytropic relation to find the results. physical…

综合物理 · 物理学 2014-03-11 Rishi Kumar Tiwari , Mukesh Sharma , Sonia Sharma

The present study deals with spatially homogeneous and totally anisotropic Bianchi type V cosmological model in presence of bulk viscous fluid source with time dependent gravitational constant G and cosmological term Lambda. The coefficient…

广义相对论与量子宇宙学 · 物理学 2022-04-22 Nawsad Ali

We discuss a spatially homogeneous and anisotropic Bianchi type-I space-time with two fluids as the content of the Universe: matter and holographic dark energy in the framework of general relativity. To get the exact solutions of Einstein's…

广义相对论与量子宇宙学 · 物理学 2023-02-03 M. Koussour , M. Bennai

Bianchi type III string cosmological models with bulk viscous fluid for massive string are investigated. To get the determinate model of the universe, we have assumed that the coefficient of bulk viscosity ($\xi$) is inversely proportional…

广义相对论与量子宇宙学 · 物理学 2009-03-19 Raj Bali , Anirudh Pradhan

The behaviour of magnetic field in anisotropic Bianchi type I cosmological model for bulk viscous distribution is investigated. The distribution consists of an electrically neutral viscous fluid with an infinite electrical conductivity. It…

广义相对论与量子宇宙学 · 物理学 2014-11-17 Anirudh Pradhan , Sanjay Kumar Singh

New dark energy models in anisotropic Bianchi type-I (B-I) space-time with variable EoS parameter and constant deceleration parameter have been investigated in the present paper. The Einstein's field equations have been solved by applying a…

综合物理 · 物理学 2011-07-15 Anirudh Pradhan , H. Amirhashchi , Bijan Saha

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

We investigated a bulk viscous fluid universe with cosmological constant {\Lambda} by assuming that the bulk viscosity to be proportional to the Hubble parameter. We found that for an expanding universe, the (relative) matter density will…

广义相对论与量子宇宙学 · 物理学 2024-01-25 Jinwen Hu , Huan Hu

Keeping in mind the current picture of an accelerating and flat Universe, some specific dynamical models of the cosmological term $\Lambda$ have been selected for investigating the nature of dark energy. Connecting the free parameters of…

天体物理学 · 物理学 2008-11-26 Saibal Ray , Utpal Mukhopadhyay , Xin-He Meng

We study the late acceleration of the universe by incorporating bulk viscous matter with the running vacuum. The vacuum energy density varies as the squares of the Hubble parameter ($\rho_{\Lambda}\propto H^2$), and the coefficient of bulk…

广义相对论与量子宇宙学 · 物理学 2022-04-27 Sarath N , Jerin Mohan N D , Titus K Mathew

In this paper, we have analyzed the significance of bulk viscosity in an axially symmetric Bianchi type-I model to study the accelerated expansion of the universe. We have considered four bulk viscosity parameterizations for the…

广义相对论与量子宇宙学 · 物理学 2022-12-21 Archana Dixit , Anirudh Pradhan , Vinod Kumar Bhardwaj , A. Beesham

Anisotropic Bianchi-III cosmological model is investigated with variable gravitational and cosmological constants in the framework of Einstein's general relativity. The shear scalar is considered to be proportional to the expansion scalar.…

广义相对论与量子宇宙学 · 物理学 2015-06-23 S. K. Tripathy , D. Behera , T. R. Routray

We consider a self-consistent system of Bianchi type-I (BI) gravitational field and a binary mixture of perfect fluid and dark energy. The perfect fluid is taken to be the one obeying the usual equation of state, i.e., $p = \zeta \ve$, with…

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

Einstein's field equations for stationary Bianchi type II models with a perfect fluid source are investigated. The field equations are rewritten as a system of autonomous first order differential equations. Dimensionless variables are…

广义相对论与量子宇宙学 · 物理学 2009-10-30 Ulf S. Nilsson , C. Uggla

We consider a nonsingular deflationary cosmological model with decaying vacuum energy density in universes of arbitrary spatial curvature. Irrespective of the value of $k$, the models are characterized by an arbitrary time scale $H_I^{-1}$…

天体物理学 · 物理学 2009-10-28 J. A. S. Lima , M. Trodden

Within the framework of Bianchi type-II (BII) cosmological model the behavior of matter distribution has been considered. It is shown that the non-zero off-diagonal component of Einstein tensor implies some severe restriction on the choice…

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

Exact solutions of the Einstein's field equations describing a spherically symmetric cosmological model without a big bang or any other kind of singularity recently obtained by Dadhich and Patel (2000) are revisited. The matter content of…

广义相对论与量子宇宙学 · 物理学 2010-11-19 Anirudh Pradhan , Kashika Srivastava , Amrit Lal Ahuja