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

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In order to study if the bulk viscosity may induce a big rip singularity on the flat FRW cosmologies, we investigate dissipative processes in the universe within the framework of the standard Eckart theory of relativistic irreversible…

High Energy Physics - Theory · Physics 2008-11-26 Mauricio Cataldo , Norman Cruz , Samuel Lepe

We propose a new approach to models of general compressible viscous fluids based on the concept of dissipative solutions. These are weak solutions satisfying the underlying equations modulo a defect measure. A dissipative solution coincides…

Analysis of PDEs · Mathematics 2020-01-01 Anna Abbatiello , Eduard Feireisl , Antonin Novotny

The recent theory of 't Hooft [ Nucl. Phys. Suppl. {\bf 68}, 174 (1998)] models the black hole as a system endowed with an envelope of matter that obeys an equation of state in the form $ p=(\gamma -1)\rho$, and acts as a source in…

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

Based on the assumption that the dark energy possessing bulk viscosity is homogenously and isotropically permeated in the universe, we propose three new viscous dark energy (VDE) models to characterize the accelerating universe. By…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-30 Deng Wang , Yang-Jie Yan , Xin-He Meng

We have investigated an LRS Bianchi Type I models with bulk viscosity in the cosmological theory based on Lyra's geometry. A new class of exact solutions have been obtained by considering a time-dependent displacement field for a constant…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Anirudh Pradhan , Hare Ram Pandey

We study effects of viscous fluid coupled with dark matter in our universe. We consider bulk viscosity in the cosmic fluid and we suppose the existence of a coupling between fluid and dark matter, in order to reproduce a stable de Sitter…

General Relativity and Quantum Cosmology · Physics 2013-10-30 Lorenzo Sebastiani

The general solution of the gravitational field equations in the flat Friedmann-Robertson-Walker geometry is obtained in the framework of the full Israel-Stewart-Hiscock theory for a bulk viscous stiff cosmological fluid, with bulk…

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

For temperatures $T$ ranging from a few MeV up to TeV and energy density $\rho$ up to $10^{16}~$GeV/fm$^3$, the bulk viscosity $\zeta$ is calculated in non-perturbation (up, down, strange, charm, and bottom) and perturbation theories with…

High Energy Physics - Phenomenology · Physics 2021-10-06 Abdel Nasser Tawfik , Carsten Greiner

This paper is a continuation of the works in \cite{Euler} and \cite{NS}, where the authors have established the global existence of smooth compressible flows in infinitely expanding balls for inviscid gases and viscid gases, respectively.…

Analysis of PDEs · Mathematics 2017-06-06 Huicheng Yin , Wenbin Zhao

We review analytical solutions of the Einstein equations which are expressed in terms of elementary functions and describe Friedmann-Lema\^itre-Robertson-Walker universes sourced by multiple (real or effective) perfect fluids with constant…

General Relativity and Quantum Cosmology · Physics 2021-12-15 Valerio Faraoni , Sonia Jose , Steve Dussault

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

We present a discussion of the effects induced by bulk viscosity either on the very early Universe stability and on the dynamics associated to the extreme gravitational collapse of a gas cloud. In both cases the viscosity coefficient is…

General Relativity and Quantum Cosmology · Physics 2009-03-24 Nakia Carlevaro , Giovanni Montani

We develop a theory of viscous dissipation in one-dimensional single-component quantum liquids at low temperatures. Such liquids are characterized by a single viscosity coefficient, the bulk viscosity. We show that for a generic interaction…

Strongly Correlated Electrons · Physics 2017-07-25 K. A. Matveev , M. Pustilnik

New, analytic solutions of relativistic viscous hydrodynamics are presented, describing expanding fireballs with Hubble-like velocity profile and ellipsoidal symmetry, similar to fireballs created in heavy ion collisions. We find that with…

Nuclear Theory · Physics 2021-05-17 M. Csanad , M. I. Nagy , Z. F. Jiang , T. Csorgo

For periodic initial data with the density allowing vacuum, we establish the global existence and exponential decay of weak, strong and classical solutions to the two-dimensional(2D) compressible Navier-Stokes equations when the bulk…

Analysis of PDEs · Mathematics 2025-07-03 Qinghao Lei , Chengfeng Xiong

We have analyzed a nonsingular model with a variable cosmological term following the Carvalho {\it et al}. ansatz. The model was shown to approximate to the model of Freese {\it et al}. in one direction and to the \"{O}zer-Taha in the…

General Relativity and Quantum Cosmology · Physics 2017-06-15 Arbab I. Arbab

We study the limiting behavior of the solutions of Euler equations of one-dimensional compressible fluid flow as the pressure like term vanishes. This system can be thought of as an approximation for the one dimensional model for large…

Analysis of PDEs · Mathematics 2018-03-06 Manas Ranjan Sahoo , Abhrojyoti Sen

In this paper we discuss some consequences of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. The latter takes into account the dissipative effects (bulk viscosity) arising from…

General Relativity and Quantum Cosmology · Physics 2015-06-23 A. Iorio , G. Lambiase

We discuss influences of bulk viscosity on the Early Universe, which is modeled by Friedmann-Robertson-Walker metric and Einstein field equations. We assume that the matter filling the isotropic and homogeneous background is relativistic…

General Relativity and Quantum Cosmology · Physics 2009-12-02 A. Tawfik , H. Mansour , M. Wahba

We consider the gravitational clustering of a multicomponent fluid in an expanding Newtonian universe, taking into account the mutual gravitational interactions of the medium. We obtain a set of exact and approximate solutions for two fluid…

Astrophysics · Physics 2026-02-19 D. Fargion