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Related papers: Shear Viscosity to Entropy Density Ratio in Six De…

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Shear viscosity \eta and entropy density s of a hadronic resonance gas are calculated using the Chapman-Enskog and virial expansion methods using the K-matrix parametrization of hadronic cross sections which preserves the unitarity of the T…

High Energy Physics - Phenomenology · Physics 2015-06-16 Anton Wiranata , Volker Koch , Madappa Prakash , Xin Nian Wang

Exact values for bulk and shear viscosity are important to characterize a fluid and they are a necessary input for a continuum description. Here we present two novel methods to compute bulk viscosities by non-equilibrium molecular dynamics…

Soft Condensed Matter · Physics 2016-06-22 Gerhard Jung , Friederike Schmid

We estimate the effects of viscosity on the phase space distribution appearing in the Cooper-Frye formula within the framework of the Grad's fourteen moment method and find that there are non-trivialities in the discussion of a…

Nuclear Theory · Physics 2009-11-18 Akihiko Monnai , Tetsufumi Hirano

We revisit the computation of the shear viscosity to entropy ratio $\eta/s$ at finite chemical potential in a holographic model that takes into account the quantum fluctuations in the IR region of near-extremal black branes. Such quantum…

High Energy Physics - Theory · Physics 2026-03-05 Sera Cremonini , Li Li , Xiao-Long Liu , Jun Nian

The viscosity of strongly interacting systems is a topic of great interest in diverse fields. We focus here on the bulk and shear viscosities of \emph{non-relativistic} quantum fluids, with particular emphasis on strongly interacting…

Quantum Gases · Physics 2014-11-20 Edward Taylor , Mohit Randeria

In this paper we introduce the black brane solutions in AdS space in 4-dimensional (4D) Einstein-Gauss-Bonnet-Yang-Mills theory in the presence of string cloud and quintessence. Shear viscosity to entropy density ratio is computed via…

High Energy Physics - Theory · Physics 2023-12-20 Mehdi Sadeghi

We calculate the shear viscosity $\eta$ of a quark plasma through the two-flavor Nambu-Jona-Lasinio (NJL) model in the chiral limit, at finite temperature $T$, and baryon number chemical potential $\mu_B$. We solve the Boltzmann equation by…

High Energy Physics - Phenomenology · Physics 2015-06-22 Çağlar Doğan

In this paper we address the ratio of the shear viscosity to entropy density $\eta/s$ in bosonic and fermionic superfluids. A small $\eta/s$ is associated with nearly perfect fluidity, and more general measures of the fluidity…

Quantum Gases · Physics 2015-06-22 Rufus Boyack , Hao Guo , K. Levin

We compute the bulk, $\zeta$, and shear, $\eta$, viscosity over entropy density, $s$, for the QCD matter formed in small collision systems at LHC. We consider a scenario of the String Percolation Model by proposing a global form of the…

High Energy Physics - Phenomenology · Physics 2023-12-06 J. R. Alvarado García , I. Bautista , A. Fernández Téllez , P. Fierro

We compute the shear viscosity, $\eta$, at general temperatures $T$, in a BCS-BEC crossover scheme which is demonstrably consistent with conservation laws. The study of $\eta$ is important because it constrains microscopic theories by…

Quantum Gases · Physics 2011-08-04 H. Guo , D. Wulin , C. C. Chien , K. Levin

Recent Bayesian analyses of heavy ion collision data have established a non-trivial temperature dependence of the shear and bulk viscosity per entropy. Motivated by this, we consider higher derivative corrections to realistic, bottom-up…

High Energy Physics - Theory · Physics 2025-10-22 Thomas Apostolidis , Umut Gürsoy , Edwan Préau

Based on the previous paper arXiv:1207.5309, we investigate the possibility to find out the bulk viscosity of dual fluid at the finite cutoff surface via gravity/fluid correspondence in Einstein-Maxwell gravity. We find that if we adopt new…

High Energy Physics - Theory · Physics 2014-04-15 Ya-Peng Hu , Yu Tian , Xiao-Ning Wu

An effective shear viscosity in central Au+Au collisions is estimated in the range of incident energies 3.3 GeV $\le \sqrt{s_{NN}}\le$ 39 GeV. The simulations are performed within a three-fluid model employing three different equations of…

Nuclear Theory · Physics 2016-04-13 Yu. B. Ivanov , A. A. Soldatov

We propose a general formula for calculating the entanglement entropy in theories dual to higher derivative gravity where the Lagrangian is a contraction of Riemann tensors. Our formula consists of Wald's formula for the black hole entropy,…

High Energy Physics - Theory · Physics 2014-01-16 Xi Dong

It was recently conjectured that the ratio of the shear viscosity to entropy density, $ \eta/ s$, for any fluid always exceeds $\hbar/(4 \pi k_B)$. This conjecture was motivated by quantum field theoretic results obtained via the AdS/CFT…

High Energy Physics - Theory · Physics 2008-11-26 Thomas D. Cohen

It is now well understood that the coefficient of shear viscosity of boundary fluid can be obtained from the horizon values of the effective coupling of transverse graviton in bulk spacetime. In this paper we observe that to find the shear…

High Energy Physics - Theory · Physics 2011-01-17 Nabamita Banerjee , Suvankar Dutta

The shear viscosity bound violation in Einstein gravity for anisotropic black branes is discussed, with the aim of constraining the deviation of the shear viscosity-entropy density ratio from the shear viscosity bound using causality and…

High Energy Physics - Theory · Physics 2016-02-02 Xian-Hui Ge

We solve second order relativistic hydrodynamics equations for a boost-invariant 1+1-dimensional expanding fluid with an equation of state taken from lattice calculations of the thermodynamics of strongly coupled quark-gluon plasma. We…

High Energy Physics - Phenomenology · Physics 2010-03-19 Krishna Rajagopal , Nilesh Tripuraneni

We calculate shear viscosity and bulk viscosity in SU(3) gauge theory on the lattice at $1.5 \,T_c$. The viscosities are extracted via a Kubo formula from the reconstructed spectral function which we determine from the Euclidean-time…

High Energy Physics - Lattice · Physics 2023-07-13 Luis Altenkort , Alexander M. Eller , Anthony Francis , Olaf Kaczmarek , Lukas Mazur , Guy D. Moore , Hai-Tao Shu

We estimate dissipative properties viz: shear and bulk viscosities of hadronic matter using relativistic Boltzmann equation in relaxation time approximation within ambit of excluded volume hadron resonance gas (EHRG) model. We find that at…

High Energy Physics - Phenomenology · Physics 2015-09-14 Guru Prakash Kadam , Hiranmaya Mishra