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A spatially homogeneous and locally rotationally symmetric Bianchi type-II cosmological model under the influence of both shear and bulk viscosity has been studied. Exact solutions are obtained with a barotropic equation of state between…

General Relativity and Quantum Cosmology · Physics 2021-05-11 A. Banerjee , S. B. Duttachoudhury , Abhik Kumar Sanyal

In (2+1)-dimensional hydrodynamic systems with broken parity, the shear and bulk viscosity is joined by the Hall viscosity and curl viscosity. The dual holographic model has been constructed by coupling a pseudo scalar to the gravitational…

High Energy Physics - Theory · Physics 2012-12-17 Rong-Gen Cai , Tian-Jun Li , Yong-Hui Qi , Yun-Long Zhang

We consider cosmological scenarios originating from a single imperfect fluid with bulk viscosity and apply Eckart's and both the full and the truncated M\"uller-Israel-Stewart's theories as descriptions of the non-equilibrium processes. Our…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-12 Oliver F. Piattella , Júlio C. Fabris , Winfried Zimdahl

An isotropic expansion for the QGP is proposed in curved Kasner spacetime for an experimental configuration with three dimensional set of beams. The fluid of relativistic particles has no shear viscosity but the nonzero bulk viscosity…

High Energy Physics - Theory · Physics 2012-01-06 Hristu Culetu

We study the bulk viscosity of dense matter, taking into account non-linear effects which arise in the large amplitude "supra-thermal" region where the deviation $\mu_\Delta$ of the chemical potentials from chemical equilibrium fulfills…

Nuclear Theory · Physics 2011-03-28 Mark G. Alford , Simin Mahmoodifar , Kai Schwenzer

A cosmic no-hair theorem for all initially contracting, spatially homogeneous, orthogonal Bianchi Cosmologies is derived - which shows that all such Universes asymptote to a spatially flat, isotropic Universe with the inclusion of a shear…

General Relativity and Quantum Cosmology · Physics 2021-07-21 Chandrima Ganguly

We calculate the shear (eta) and bulk (zeta) viscosities of a weakly coupled quark gluon plasma at the leading-log order with finite temperature T and quark chemical potential mu. We find that the shear viscosity to entropy density ratio…

High Energy Physics - Phenomenology · Physics 2013-05-30 Jiunn-Wei Chen , Yen-Fu Liu , Yu-Kun Song , Qun Wang

A flat FLRW cosmological model with perfect fluid comprising of variable Chaplygin gas has been studied in context of f(R; T) gravity with particle creation. The considered scale factors describe the accelerated expansion of universe due to…

General Relativity and Quantum Cosmology · Physics 2020-02-12 N. Hulke , G. P. Singh , Binaya K. Bishi , A. Singh

In this talk, we discuss one of the dissipative processes which likely take place in the Early Universe. We assume that the matter filling the isotropic and homogeneous background is to be described by a relativistic viscous fluid…

General Relativity and Quantum Cosmology · Physics 2011-10-03 A. Tawfik , T. Harko , H. Mansour , M. Wahba

We show that a general but shear-free perturbation of homogeneous and isotropic universes are necessarily silent, without any gravitational waves. We prove this in two steps. First we establish that a shear free perturbation of these…

General Relativity and Quantum Cosmology · Physics 2021-06-04 Roger M. Mayala , Rituparno Goswami , Sunil D. Maharaj

We investigate the late-time cosmic acceleration within the framework of viscous $f(T,L_m)$ gravity, where the gravitational action depends on both the torsion scalar $T$ and the matter Lagrangian $L_m$. In this context, the Universe is…

General Physics · Physics 2026-03-24 M. Koussour , Alnadhief H. A. Alfedeel , S. Muminov , J. Rayimbaev

Inflationary models and their claim to solve many of the outstanding problems in cosmology have been the subject of a great deal of debate over the last few years. A major sticking point has been the lack of both good observational and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Henk van Elst , Peter Dunsby , Reza Tavakol

A Lagrangian density for viscous quark-gluon plasma has been constructed within the fluid-like QCD framework. Gauge symmetry is preserved for all terms inside the Lagrangian, except for the viscous term. The transition mechanism from point…

Nuclear Theory · Physics 2014-10-15 T. P. Djun , B. Soegijono , T. Mart , L. T. Handoko

We perform a global analysis of curved Friedmann-Robertson-Walker cosmologies in the presence of a viscous fluid. The fluid's bulk viscosity is governed by a first order theory recently proposed in [M. M. Disconzi, T. W. Kephart, and R. J.…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Giovanni Acquaviva , Aroonkumar Beesham

We consider how the five-dimensional Randall-Sundrum (one-brane) theory becomes modified when account is taken of the bulk viscosity of the cosmic fluid on the brane. We focus on the plasma era between $10^{12}$K (muon pair annihilation) to…

General Relativity and Quantum Cosmology · Physics 2015-02-23 Iver Brevik

Bianchi I cosmological models consisting of a fluid with both bulk and shear viscosity are studied. It is shown how the dynamical importance of the shear and the fluid density change in the course of evolution. Exact solutions with an…

General Relativity and Quantum Cosmology · Physics 2021-03-15 A. Banerjee , S. B. Duttachoudhury , Abhik Kumar Sanyal

We develop the first causal and stable theory of a bulk-viscous relativistic pseudoplastic (or dilatant) fluid. This new formalism brings to light the rheological properties of several relativistic physical systems. Neutron star collisions…

General Relativity and Quantum Cosmology · Physics 2024-05-30 Lorenzo Gavassino , Jorge Noronha

In an open Friedmann-Robertson-Walker (FRW) space background, we study the classical and quantum cosmological models in the framework of the recently proposed nonlinear massive gravity theory. Although the constraints which are present in…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Babak Vakili , Nima Khosravi

We consider a simplified model of quantum gravity using a mini-superspace description of an isotropic and homogeneous universe with dust. We derive the corresponding Friedmann equations for the scale factor, which now contain a dependence…

General Relativity and Quantum Cosmology · Physics 2020-04-03 Thibaut Demaerel , Christian Maes , Ward Struyve

A theoretical framework for the calculation of shear and bulk viscosities of hadronic matter at finite temperature is presented. The framework is based on the quasi-particle picture. It allows for an arbitrary number of hadron species with…

Nuclear Theory · Physics 2011-02-01 P. Chakraborty , J. I. Kapusta
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