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Related papers: Inhomogeneous Bulk Viscous Fluid Universe with Ele…

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We consider a cosmological model dominated by stiff fluid with a constant bulk viscosity. We classify all the possible cases of the universe predicted by the model and analyzing the scale factor, density as well as the curvature scalar. We…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Titus K Mathew , Aswathy M B , Manoj M

We discuss phenomenology of quantum vacuum. Phenomenology of macroscopic systems has three sources: thermodynamics, topology and symmetry. Thermodynamics of the self-sustained vacuum allows us to treat the problems related to the vacuum…

Other Condensed Matter · Physics 2013-09-13 G. E. Volovik

The general solution of the gravitational field equations for a full causal bulk viscous stiff cosmological fluid, with bulk viscosity coefficient proportional to the energy density to the power 1/4, is obtained in the flat…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. K. Mak , T. Harko

Considering the condition on conservation of energy momentum tensor (EMT), we study late time cosmological solutions in the context of $f(R,T)=R+\alpha T^{n}$ gravity (where $\alpha$ and $n$ are constants) in a flat FLRW spacetime. The…

General Relativity and Quantum Cosmology · Physics 2024-03-06 Hamid Shabani , Norman Cruz , Amir Hadi Ziaie

We have explored the shear viscosity and electrical conductivity calculations for bosonic and fermionic medium, which goes from without to with magnetic field picture and then their simplified massless expressions. In presence of magnetic…

High Energy Physics - Phenomenology · Physics 2020-10-12 Jayanta Dey , Sarthak Satapathy , Prasanta Murmu , Sabyasachi Ghosh

In this work, we introduce an effective model for both ideal and viscous fluid dynamics within the framework of kinetic field theory (KFT). The main application we have in mind is cosmic structure formation where gaseous components need to…

Statistical Mechanics · Physics 2018-11-01 C. Viermann , J. T. Schneider , R. Lilow , F. Fabis , C. Littek , E. Kozlikin , M. Bartelmann

In this paper, we study in detail a perfect fluid cosmological model with time-varying "constants" using dimensional analysis and the symmetry method. We examine the case of variable "constants" in detail without considering the perfect…

General Relativity and Quantum Cosmology · Physics 2009-12-30 José Antonio Belinchón , Indrajit Chakrabarty

In this paper we study the exact solutions for a viscous fluid distribution in Bianchi II, VIII, and IX models. The metric is simplified by assuming a relationship between the coefficients and the metric tensor. Solutions are obtained in…

General Relativity and Quantum Cosmology · Physics 2021-05-25 A. Banerjee , Abhik Kumar Sanyal , S. Chakraborty

We investigate exact solutions of the Einstein-Maxwell equations with the cosmological constant where the source of the gravitational field consists of a magnetic field and dust. In particular, we restrict our study to the case of Bianchi…

General Relativity and Quantum Cosmology · Physics 2025-05-23 Martin Zofka , Kjell Rosquist

We present the class of regular homogeneous T-models with vacuum dark fluid, associated with a variable cosmological term. The vacuum fluid is defined by the symmetry of its stress-energy tensor, i.e., its invariance under Lorentz boosts in…

General Relativity and Quantum Cosmology · Physics 2008-11-26 K. A. Bronnikov , I. G. Dymnikova

We calculate the vacuum averages of the energy-momentum tensor associated with a massless left-handed spinor fields due to magnetic fluxes on idealized cosmic string spacetime. In this analysis three distinct configurations of magnetic…

High Energy Physics - Theory · Physics 2009-11-10 J. Spinelly , E. R. Bezerra de Mello

We review spacetime dynamics in the presence of large-scale electromagnetic fields and then consider the effects of the magnetic component on perturbations to a spatially homogeneous and isotropic universe. Using covariant techniques, we…

Astrophysics · Physics 2008-11-26 J. D. Barrow , R. Maartens , C. G. Tsagas

We show under the assumption of small data that solutions to the Einstein-Vlasov system with a pure magnetic field and Bianchi I symmetry isotropise and tend to dust solutions. We also obtain the decay rates for the main variables. This…

General Relativity and Quantum Cosmology · Physics 2024-06-18 Ho Lee , Ernesto Nungesser

An overview of some recent developments in inhomogeneous models is presented. As the volume and precision of cosmological data improves, it will become more and more essential to understand the non-linear behaviour of the Einstein field…

General Relativity and Quantum Cosmology · Physics 2010-01-06 Charles Hellaby

In our previous works, we have analyzed the evolution of bulk viscous matter dominated universe with a more general form for bulk viscous coefficient, $\zeta=\zeta_{0}+\zeta_{1}\frac{\dot{a}}{a}+\zeta_{2}\frac{\ddot{a}}{\dot{a}}$ and also…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Athira Sasidharan , N D Jerin Mohan , Moncy V John , Titus K Mathew

A new class of cylindrically symmetric inhomogeneous string cosmological models is investigated. To get the deterministic solution, it has been assumed that the expansion ($\theta$) in the model is proportional to the eigen value…

General Relativity and Quantum Cosmology · Physics 2018-07-10 Anirudh Pradhan , Mukesh Kumar Mishra , Anil Kumar Yadav

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…

General Physics · Physics 2014-03-11 Rishi Kumar Tiwari , Mukesh Sharma , Sonia Sharma

The inhomogeneous distribution of matter in the non-linear regime of galaxies, clusters of galaxies and voids is described by an exact, spherically symmetric inhomogeneous solution of Einstein's gravitational field equations, corresponding…

Astrophysics · Physics 2009-11-11 J. W. Moffat

We study the effect of magnetic field on the transport properties like shear and bulk viscosities of hot and dense hadronic matter within hadron resonance gas model. We estimate the bulk viscosity using low energy theorems for bilocal…

High Energy Physics - Phenomenology · Physics 2015-03-09 Guru Kadam

Multidimensional cosmological model describing the evolution of a fluid with shear and bulk viscosity in $n$ Ricci-flat spaces is investigated. The barotropic equation of state for the density and the pressure in each space is assumed. The…

General Relativity and Quantum Cosmology · Physics 2010-04-30 V. R. Gavrilov , V. N. Melnikov , Roland Triay