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In this paper, we study the $f(T,\mathcal{T})$ gravity model in the presence of the bulk viscosity by the flat-FRW metric. The field equation is obtained by teleparallel gravity with tetrad field. The universe components are considered as…

General Relativity and Quantum Cosmology · Physics 2020-12-18 T. Mirzaei-Rezaei , Alireza Amani , E. Yusofi , S. Rouhani , M. A. Ramzanpour

Isotropic and spatially homogeneous viscous fluid cosmological models are investigated using the truncated Israel-Stewart theory of irreversible thermodynamics to model the bulk viscous pressure. The governing system of differential…

General Relativity and Quantum Cosmology · Physics 2010-04-06 A A Coley , R J van den Hoogen

In this paper, we explore an axially symmetric Bianchi type-I model of the universe with bulk viscous fluid as a source of gravitational field under the framework of Einstein's field equations by assuming barotropic bulk viscous pressure as…

General Relativity and Quantum Cosmology · Physics 2025-04-29 G. K. Goswami , Anirudh Pradhan , Vipin Chandra Dubey

We study the bulk flow of the local universe using Type Ia supernova data by considering a class of cosmological model which is spatially flat,(FRW) space-times and contains cold dark matter and $Q$ component (QCDM models) of the fluid as a…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-31 A. Salehi , M. Yarahmadi , S. Fathi

A generalized dynamical equation for the scale factor of the universe is proposed to describe the cosmological evolution, of which the $\Lambda$CDM model is a special case. It also provides a general example to show the equivalence of the…

Astrophysics · Physics 2009-11-11 J. Ren , X. H. Meng

We have considered a spatially flat, homogeneous and isotropic FLRW Universe filled with a single fluid, known as logotropic dark fluid (LDF), whose pressure evolves through a logarithmic equation of state. We use the recent Pantheon SNIa…

General Relativity and Quantum Cosmology · Physics 2021-01-15 Abdulla Al Mamon , Subhajit Saha

In this article, we investigate the observed cosmic acceleration in the framework of a cosmological $f(R,L_m)$ model dominated by bulk viscous matter in an anisotropic background. We consider the LRS Bianchi type I metric and derive the…

General Relativity and Quantum Cosmology · Physics 2023-06-14 Raja Solanki , Bina Patel , Lakhan V. Jaybhaye , P. K. Sahoo

In this work, we have studied how incorporating viscous fluids leads to exact bounce cosmological solutions in general relativity (GR) framework. Specifically, we propose a novel parameterization of bulk viscosity coefficient of the form…

General Relativity and Quantum Cosmology · Physics 2024-07-23 Rajdeep Mazumdar , Mrinnoy M. Gohain , Kalyan Bhuyan

Cylindrically symmetric inhomogeneous cosmological model for bulk viscous fluid distribution with electromagnetic field is obtained. The source of the magnetic field is due to an electric current produced along the z-axis. $F_{12}$ is the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Anirudh Pradhan , Vandana Rai , Kanti Jotania

A dissipative model of the Universe based on the causal relativistic truncated Israel-Stewart theory is analysed in the context of recent accelerated expansion of the Universe. The bulk viscosity and relaxation time are taken as…

General Relativity and Quantum Cosmology · Physics 2021-08-13 Jerin Mohan N D , Titus K Mathew

The behaviour of solutions to the Einstein equations with a causal viscous fluid source is investigated. In this model we consider a spatially flat Robertson-Walker metric, the bulk viscosity coefficient is related to the energy density as…

General Relativity and Quantum Cosmology · Physics 2012-08-09 Luis P. Chimento , Alejandro S. Jakubi

This article explores the impact of bulk viscosity on understanding the universe's accelerated expansion within the context of modified $f(T,\mathcal{T})$ gravity, which is an extension of the $f(T)$ gravitational theory, allowing a broad…

General Relativity and Quantum Cosmology · Physics 2024-07-29 Raja Solanki , Aaqid Bhat , P. K. Sahoo

We analyze characteristic properties of two different cosmological models: (i) a one-component dark energy model where the bulk viscosity $\zeta$ is associated with the fluid as a whole, and (ii) a two-component model where $\zeta$ is…

General Relativity and Quantum Cosmology · Physics 2017-01-16 Ben David Normann , Iver Brevik

Assuming that the matter filling the background geometry in the Early Universe was a free gas and no phase transitions took place, we discuss the thermodynamics of this closed system using classical approaches. We found that essential…

General Relativity and Quantum Cosmology · Physics 2010-11-11 A. Tawfik

We study a full causal bulk viscous cosmological model with flat FRW symmetries and where the ``constants'' $G,c$ and $\Lambda $ vary. We take into account the possible effects of a $c-$variable into the curvature tensor in order to outline…

General Relativity and Quantum Cosmology · Physics 2016-08-16 J. A. Belinchón

Bulk viscosity in cold dark matter is an appealing feature that introduces distinctive phenomenological effects in the cosmological setting as compared to the $\Lambda$CDM model. Under this view, we propose a general parametrization of the…

General Relativity and Quantum Cosmology · Physics 2023-08-24 Gabriel Gómez , Guillermo Palma , Ángel Rincón , Norman Cruz , Esteban González

We propose a new model for the viscosity of cosmic matters, which can be applied to different epochs of the universe. Using this model, we include the bulk viscosities as practical corrections to the perfect fluid models of the baryonic and…

General Relativity and Quantum Cosmology · Physics 2022-11-30 Jing Yang , Rui-Hui Lin , Xiang-Hua Zhai

In this paper, we have proposed a model of accelerating Universe with binary mixture of bulk viscous fluid and dark energy. and probed the model parameters: present values of Hubble's constant $H_{0}$, Equation of state paper of dark energy…

General Relativity and Quantum Cosmology · Physics 2021-08-18 Nishant Singla , M. K. Gupta , Anil Kumar Yadav , G. K. Goswami

In this paper, we have presented bulk viscous cosmological model of the universe in the modified gravity theory in which the Lagragian of the gravitational action contains a general function $f(R, T) $, where $R$ and $T$ denote the…

General Relativity and Quantum Cosmology · Physics 2019-07-05 Partha Sarathi Debnath

We present and constrain a cosmological model which component is a pressureless fluid with bulk viscosity as an explanation for the present accelerated expansion of the universe. We study the particular model of a constant bulk viscosity…

General Relativity and Quantum Cosmology · Physics 2009-03-24 Arturo Avelino , U. Nucamendi , F. S. Guzmán
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