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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

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

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

Spatially homogeneous and anisotropic Bianchi type V space-time with bulk viscous fluid source and time varying gravitational constant $G$ and cosmological term $\Lambda$ are considered. Coefficient of bulk viscosity $\zeta$ is assumed as a…

广义相对论与量子宇宙学 · 物理学 2012-05-25 Prashant S. Baghel , J. P. Singh

In this paper we are to study homogeneous and anisotropic Bianchi type-V universe in presence of bulk viscous fluid source of matter with time function gravitational constant G and cosmological term lambda. The viscosity coefficient is…

广义相对论与量子宇宙学 · 物理学 2023-05-19 Nawsad Ali

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 bulk viscous fluid for an LRS Bianchi type-I spacetime is obtained by using deceleration parameter as variable. The value of Hubble's constant $H_{0}$ is found to be less…

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

In this paper, we have investigated a bulk viscous anisotropic Universe and constrained its model parameters with recent $H(z)$ and Pantheon compilation data. Using cosmic chronometric technique, we estimate the present value of Hubble's…

广义相对论与量子宇宙学 · 物理学 2021-06-10 G. K. Goswami , Anil Kumar Yadav , B. Mishra , S. K. Tripathy

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

We have examined the cosmological actions of LRS (Locally Rationally Symmetric) Bianchi type-I universe model in $f(R,T^\psi)$ gravity. For this, we have estimated the Hubble parameter, the effective equation of state parameter…

广义相对论与量子宇宙学 · 物理学 2026-01-07 Mohit Thakre , Praveen Kumar Dhankar , Safiqul Islam , Parbati Sahoo , Farook Rahaman , Behnam Pourhassan

We use Gaussian processes in combination with MCMC method to place constraints on cosmological parameters of three dark energy models including flat and curved FRW and Bianchi type I spacetimes. To do so, we use recently compiled 36…

宇宙学与河外天体物理 · 物理学 2019-01-16 Hassan Amirhashchi , Soroush Amirhashchi

In this study, we investigate a locally rotationally symmetric (LRS) Bianchi type-I cosmological model in non-linear form of $f(Q)$ gravity with observational constraints. We solved the modified Einstein's field equations with a viscous…

广义相对论与量子宇宙学 · 物理学 2025-09-10 Dinesh Chandra Maurya

In this study, we have explored a scalar field cosmological model in the axially symmetric Bianchi type-I universe. In this study, our aim is to constrain the scalar field dark energy model in an anisotropic background. For this purpose,…

广义相对论与量子宇宙学 · 物理学 2025-11-19 Vinod Kumar Bhardwaj , Anil Kumar Yadav

Bianchi type V viscous fluid cosmological model for barotropic fluid distribution with varying cosmological term $\Lambda$ is investigated. We have examined a cosmological scenario proposing a variation law for Hubble parameter $H$ in the…

广义相对论与量子宇宙学 · 物理学 2015-06-04 Raj Bali , Pratibha Singh , J. P. Singh

Bianchi type I magnetized cosmological models in the presence of a bulk viscous fluid are investigated. The source of the magnetic field is due to an electric current produced along x-axis. The distribution consists of an electrically…

广义相对论与量子宇宙学 · 物理学 2014-11-17 Anirudh Pradhan , Om Prakash Pandey

From a phenomenological point of view, we analyze the dynamics of the Universe at late times by introducing a polynomial and hyperbolic bulk viscosity into the Einstein field equations respectively. We constrain their free parameters using…

综合物理 · 物理学 2019-10-01 A. Hernández-Almada

In this work, we study a cosmological model of Bianchi type-I Universe in teleparallel gravity for a perfect fluid. To obtain the cosmological solution of the model, we assume that the deceleration parameter is a linear function of the…

广义相对论与量子宇宙学 · 物理学 2022-05-25 M. Koussour , M. Bennai

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…

It is well known that flat FRW metric is a special case of Bianchi type I spacetime. In this paper, we use 38 Hubble parameter, $H(z)$, measurements at intermediate redshifts $0.07\leq z\leq 2.36$ and its joint combination with the latest…

宇宙学与河外天体物理 · 物理学 2018-03-21 Hassan Amirhashchi

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
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