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Related papers: Cosmological Implications of QGP Bulk Viscosity

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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

We present a unified description of the high temperature phase of QCD, the so-called quark-gluon plasma, in a regime where the effective gauge coupling $g$ is sufficiently small to allow for weak coupling calculations. The main focuss is…

High Energy Physics - Phenomenology · Physics 2009-11-07 Jean-Paul Blaizot , Edmond Iancu

We investigate the temperature dependence of the shear viscosity ($\eta$) and bulk viscosity ($\zeta$) of the gluon plasma using lattice QCD over the range 0.76--2.25$\,T_c$, extending from below the transition temperature $T_c$ across the…

High Energy Physics - Lattice · Physics 2026-04-08 Heng-Tong Ding , Hai-Tao Shu , Cheng Zhang

In this study, we investigate the thermodynamic properties of an ideal Quark-Gluon Plasma (QGP) at a vanishing chemical potential, under the influence of quantum gravitational effects, specifically incorporating the Linear-Quadratic…

High Energy Physics - Theory · Physics 2025-01-03 Djamel Eddine Zenkhri , Abdelhakim Benkrane

In nucleus-nucleus collisions at relativistic energies a new kind of matter is created, the Quark-Gluon Plasma (QGP). The phase diagram of such matter and the chemical freeze-out points will be presented in connection to the pseudo-critical…

High Energy Physics - Phenomenology · Physics 2022-12-27 Peter Braun-Munzinger , Anar Rustamov , Johanna Stachel

A simple model of uniformly expanding, homogeneous Universe with a bulk viscosity is studied wherein the inflationary density decays due to viscous dissipation during the expansion phase of the Universe. The model is shown to generate the…

General Relativity and Quantum Cosmology · Physics 2020-10-14 Sanved Kolekar , S. Shankaranarayanan , S. M. Chitre

The quantum gravitational scale of inflation is calculated by finding a sharp probability peak in the distribution function of chaotic inflationary cosmologies driven by a scalar field with large negative constant $\xi$ of nonminimal…

General Relativity and Quantum Cosmology · Physics 2009-10-22 A. O. Barvinsky , A. Yu. Kamenshchik

We consider a cosmological model dominated by bulk viscous matter with total bulk viscosity coefficient proportional to the velocity and acceleration of the expansion of the universe in such a way that…

General Relativity and Quantum Cosmology · Physics 2016-04-28 Athira Sasidharan , Titus K. Mathew

We consider the influence of the perturbative bulk viscosity on the evolution of the Hubble parameter in the QCD era of the early Universe. For the geometry of the Universe we assume the homogeneous and isotropic…

General Relativity and Quantum Cosmology · Physics 2010-11-24 A. Tawfik , M. Wahba , H. Mansour , T. Harko

We review recent developments in lattice siumulations of the equation of state, order of the thermal phase transition and the determination of the pseudo-critical temperature in (2+1)-flavor QCD. Owing to the increasing computer power, new…

High Energy Physics - Phenomenology · Physics 2008-11-26 Tetsuo Hatsuda

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

Some recent developments concerning the role of strange quark matter for astrophysical systems and the QCD phase transition in the early universe are addressed. Causality constraints of the soft nuclear equation of state as extracted from…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Tillmann Boeckel , Matthias Hempel , Irina Sagert , Giuseppe Pagliara , Basil Sa'd , Jurgen Schaffner-Bielich

Quantum gravitational back-reaction offers the potential of simultaneously resolving the problem of the cosmological constant and providing a natural model of inflation in which scalars play no special role. In this model inflation begins…

Astrophysics · Physics 2007-05-23 R. P. Woodard

We here investigate bulk-viscosity driven quasi de-Sitter inflation, that is, the period of accelerated expansion in the early universe during which $-\dot{H}\ll H^2$, with $H(t)$ being the Hubble expansion rate. We do so in the framework…

General Relativity and Quantum Cosmology · Physics 2024-02-21 Sayantani Lahiri , Luciano Rezzolla

This thesis is dedicated to studying cosmological inflation, which is a period of accelerated expansion in the very early Universe that is required to explain the observed anisotropies in the cosmic microwave background. Inflation, when…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-02 Chris Pattison

Typically cold inflation with positive vacuum energy density dilutes all matter except the quan- tum fluctuations which are stretched outside the Hubble patch during inflation. However the cyclic- inflation scenario, where the universe…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Tirthabir Biswas , Tomi Koivisto , Anupam Mazumdar

Based on hot big bang theory, the cosmological matter is conjectured to undergo QCD phase transition(s) to hadrons, when the universe was about $1-10 \mu$s old. In the present work, we study the quark-hadron phase transition, by taking into…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-26 A. Tawfik , T. Harko

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

Our knowledge of the equation of state of the quark gluon plasma has been continuously growing due to the experimental results from heavy ion collisions, due to recent astrophysical measurements and also due to the advances in lattice QCD…

High Energy Physics - Phenomenology · Physics 2015-02-27 S. M. Sanches , F. S. Navarra , D. A. Fogaça

Relativistic heavy ion collisions generate nuclear-sized droplets of quark-gluon plasma (QGP) that exhibit nearly inviscid hydrodynamic expansion. Smaller collision systems such as p+Au, d+Au, and $^{3}$He+Au at the Relativistic Heavy Ion…

Nuclear Theory · Physics 2020-04-29 M. Byres , S. H. Lim , C. McGinn , J. Ouellette , J. L. Nagle