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Related papers: General Bulk-Viscous Solutions and Estimates of Bu…

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The article communicates an alternative route to suffice the late-time acceleration considering a bulk viscous fluid with viscosity coefficient $\zeta =\zeta _{0}+ \zeta _{1} H + \zeta _{2} H^{2}$, where $\zeta _{0}, \zeta _{1}, \zeta _{2}$…

General Relativity and Quantum Cosmology · Physics 2020-07-20 Simran Arora , Snehasish Bhattacharjee , P. K. Sahoo

The present paper is dedicated to the global large solutions and incompressible limit for the compressible flow of liquid crystals under the assumption on almost constant density and large volume viscosity. The result is based on Fourier…

Analysis of PDEs · Mathematics 2018-05-29 Xiaoping Zhai , Zhi-min Chen

The concept of negative temperatures has occasionally been used in connection with quantum systems. A recent example of this sort is reported in the paper of S. Braun et al. [Science 339,52 (2013)], where an attractively interacting…

General Relativity and Quantum Cosmology · Physics 2013-10-01 Iver Brevik , Øyvind Grøn

In this paper, we have investigated the late time cosmic acceleration issue in the context of $f(R,T)$ gravity. The matter field is considered to be that of viscous fluid. The model has been framed as a mathematical formalism and the effect…

General Relativity and Quantum Cosmology · Physics 2022-07-19 Sankarsan Tarai , Pratik P Ray , B. Mishra , S. K. Tripathy

The dilute Fermi gas at unitarity is scale invariant and its bulk viscosity vanishes. We compute the leading contribution to the bulk viscosity when the scattering length is not infinite. A measure of scale breaking is provided by the ratio…

Quantum Gases · Physics 2013-05-22 Thomas Schaefer , Kevin Dusling

We consider the evolution of a flat, isotropic and homogeneous Friedmann-Robertson-Walker Universe, filled with a causal bulk viscous cosmological fluid, that can be characterized by an ultra-relativistic equation of state and bulk…

General Relativity and Quantum Cosmology · Physics 2011-10-05 A. Tawfik , M. Wahba , H. Mansour , T. Harko

The full causal M\"uller-Israel-Stewart (MIS) theory of dissipative processes in relativistic fluids is applied to a flat, homogeneous and isotropic universe with bulk viscosity. It is clarified in which sense the so called truncated…

Astrophysics · Physics 2008-11-26 Winfried Zimdahl

As recently found by Youm [hep-th/0201268], the entropy of the universe will no longer be expressible in the conventional Cardy-Verlinde form if one relaxes the radiation dominance state equation and instead assumes a more general equation…

General Relativity and Quantum Cosmology · Physics 2009-01-14 I. Brevik

We investigate the phase space dynamics of a bulk viscosity model in the Eckart approach for a spatially flat Friedmann-Robertson-Walker universe. We have included two barotropic fluids and a dark energy component. One of the barotropic…

General Relativity and Quantum Cosmology · Physics 2014-10-29 Norman Cruz , Samuel Lepe , Yoelsy Leyva , Francisco Peña , Joel Saavedra

We show the analogy between a generalization of the Rayleigh-Plesset equation of bubble dynamics including surface tension, elasticity and viscosity effects with a reformulation of the Friedmann-Lema\^itre set of equations describing the…

General Physics · Physics 2020-06-08 Germain Rousseaux , Stefan C. Mancas

We describe the accelerated expansion of the late-time universe using a generalized equation of state (EoS) when account is taken of bulk viscosity. We assume a homogeneous and isotropic Friedmann-Robertson-Walker spacetime. Solutions of…

General Relativity and Quantum Cosmology · Physics 2019-08-05 I. Brevik , A. N. Makarenko , A. V. Timoshkin

The holographic principle in a radiation dominated universe, as discussed first by Verlinde (2000), is extended so as to incorporate the case of a bulk-viscous cosmic fluid. This corresponds to a non-conformally invariant theory.…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Iver Brevik

This paper is dedicated to the global existence and optimal decay estimates of strong solutions to the compressible viscoelastic flows in the whole space $\mathbb{R}^n$ with any $n\geq2$. We aim at extending those works by Qian \& Zhang and…

Analysis of PDEs · Mathematics 2022-08-08 Xinghong Pan , Jiang Xu

In this study, we explore the accelerated expansion of the universe within the framework of modified $f(Q)$ gravity. The investigation focus on the role of bulk viscosity in understanding the universe's accelerated expansion. Specifically,…

General Relativity and Quantum Cosmology · Physics 2024-07-09 Dheeraj Singh Rana , P. K. Sahoo

The microscopic formulas for the shear viscosity $\eta$, the bulk viscosity $\zeta$, and the corresponding relaxation times $\tau_\pi$ and $\tau_\Pi$ of causal dissipative relativistic fluid-dynamics are obtained at finite temperature and…

High Energy Physics - Theory · Physics 2013-05-24 Xu-Guang Huang , Tomoi Koide

The effect of bulk viscisity on the evolution of the homogeneous and isotropic cosmological models is considered. Solutions are found, with a barotropic equation of state, and a viscosity coefficient that is proportional to a power of the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Pimentel L O , Diaz-Rivera L M

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

The research on relativistic universe models with viscous fluids is reviewed. Viscosity may have been of significance during the early inflationary era, and may also be of importance for the late time evolution of the Universe. Bulk…

General Relativity and Quantum Cosmology · Physics 2014-10-01 Iver Brevik , Øyvind Grøn

We investigate the bounce cosmology induced by inhomogeneous viscous fluids in FRW space-time (non necessarly flat), taking into account the early-time acceleration after the bounce. Different forms for the scale factor and several examples…

General Relativity and Quantum Cosmology · Physics 2015-09-21 Ratbay Myrzakulov , Lorenzo Sebastiani

This paper concerns the barotropic compressible Navier-Stokes equations in a two-dimensional half-space subject to Navier-slip boundary conditions with vacuum or non-vacuum far-field density. The global existence and large-time behavior of…

Analysis of PDEs · Mathematics 2026-05-29 Qinghao Lei , Weirong Liang
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