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We probe into universes filled with Quark Gluon Plasma with non-zero viscosities. In particular, we study the evolution of a universe with non-zero shear viscosity motivated by the theoretical result of a non-vanishing shear viscosity in…

General Relativity and Quantum Cosmology · Physics 2019-10-03 Sergio Bravo Medina , Marek Nowakowski , Davide Batic

Analytical properties of the scalar expansion in the cosmic fluid are investigated, especially near the future singularity, when the fluid possesses a constant bulk viscosity \zeta. In addition, we assume that there is a Casimir-induced…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Iver Brevik , Olesya Gorbunova , Diego Saez-Gomez

The bulk viscosity, $\zeta$ and its ratio with the shear viscosity, $\zeta/\eta$ have been studied in an anisotropically expanding pure glue plasma in the presence of turbulent color fields. It has been shown that the anisotropy in the…

Nuclear Theory · Physics 2011-11-23 Vinod Chandra

This study investigates the evolution of quark gluon plasma (QGP) within a generalized Bjorken flow framework. The medium under consideration is assumed to possess a finite transverse size and to expand both radially and along the beam…

Nuclear Theory · Physics 2023-08-22 M. Karimabadi , A. F. Kord , B. Azadegan

The shear ($\eta$) and bulk ($\zeta$) viscosities are calculated in a quasiparticle relaxation time approximation for a hadron matter described within the relativistic mean-field based model with scaled hadron masses and couplings.…

Nuclear Theory · Physics 2011-05-05 A. S. Khvorostukhin , V. D. Toneev , D. N. Voskresensky

Through the consideration of spherically symmetric gravitating systems consisting of perfect fluids with linear equation of state constrained to be in a finite volume, an account is given of the properties of entropy at conditions in which…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alessandro Pesci

We present a time dependent isotropic fluid solution around a Schwarzschild black hole. We offer the solutions and discuss the effects on the field equations and the horizon. We derive the energy density, pressure and the equation of state…

General Relativity and Quantum Cosmology · Physics 2018-07-26 Metin Arik , Yorgo Senikoglu

We have studied the viscous properties as well as the Bjorken expansion of a rotating QGP medium. In the noncentral events of heavy-ion collisions, the produced medium can carry a finite angular momentum with a finite range of angular…

High Energy Physics - Phenomenology · Physics 2025-10-10 Shubhalaxmi Rath , Nicolás A. Neill

While the Kiselev black hole solution does not describe a perfect fluid quintessence, it is possible that dark energy fluid is not isotropic, and so one may hope that the solution may still describe at least locally a black hole embedded in…

General Relativity and Quantum Cosmology · Physics 2025-12-02 Jiayi Xia , Yen Chin Ong

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

Einstein's field equations in FRW space-times are coupled to the BGK equation in order to derive the stress energy tensor including dissipative effects up to second order in the thermodynamical forces. The space-time is assumed to be…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. Sandoval-Villalbazo , L. S. Garcia-Colin

Hydrodynamics provides a concise but powerful description of long-time and long-distance physics of correlated systems out of thermodynamic equilibrium. Here we construct hydrodynamic equations for nonrelativistic particles with a…

Quantum Gases · Physics 2018-12-27 Keisuke Fujii , Yusuke Nishida

In this paper, we consider the Bianchi type-I space-time with perfect fluid as matter content of the Universe in the framework of $f(Q)$ gravity (where $% Q$ is the non-metricity scalar) recently proposed by Jim\'{e}nez et al. (Phys. Rev. D…

General Relativity and Quantum Cosmology · Physics 2022-08-18 M. Koussour , S. H. Shekh , M. Bennai

We concern with the global existence and large time behavior of compressible fluids (including the inviscid gases, viscid gases, and Boltzmann gases) in an infinitely expanding ball. Such a problem is one of the interesting models in…

Analysis of PDEs · Mathematics 2018-09-26 Gang Xu , Huicheng Yin

The Shiromizu et al. \cite{SMS} covariant decomposition formalism is used to find out the brane properties rooted from the 5-dimensional Witten bubble spacetime. The non-local tensor $E_{ab}$ generated by the 5-dimensional Weyl tensor gives…

General Relativity and Quantum Cosmology · Physics 2014-02-18 Hristu Culetu

The bulk viscosity ($\zeta$) of the hadronic medium has been estimated within the ambit of the Hadron Resonance Gas (HRG) model including the Hagedorn density of states. The HRG thermodynamics within a grand canonical ensemble provides the…

Nuclear Theory · Physics 2017-04-12 Golam Sarwar , Sandeep Chatterjee , Jan-e Alam

We propose an uncertainty relation of space-time. This relation is characterized by GhT \lesssim \delta V, where T and \delta V denote a characteristic time scale and a spatial volume, respectively. Using this uncertainty relation, we give…

High Energy Physics - Theory · Physics 2008-11-26 N. Sasakura

We numerically solve fully (3+1)-dimensional relativistic hydrodynamical equation coupled with the baryon number conservation law without spatial symmetry. We discuss the effect of transverse expansion based on the deviation our numerical…

Nuclear Theory · Physics 2007-05-23 C. Nonaka , S. Muroya , O. Miyamura

An isotropic and homogeneous cosmological model with a source of dark energy is studied. That source is simulated with a viscous relativistic fluid with minimal causal correction. In this model the restrictions on the parameters coming from…

General Relativity and Quantum Cosmology · Physics 2017-04-20 Carlos E. Laciana

We present a nontrivial extension of the problem of spherical accretion of a collisionless kinetic gas into the standard Schwarzschild black hole. This extension consists of replacing the Schwarzschild black hole by generic static and…

General Relativity and Quantum Cosmology · Physics 2025-09-08 Mehrab Momennia , Olivier Sarbach