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Related papers: Shear Viscosity in Weakly Coupled N-Component Scal…

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We consider charged dilatonic black branes in AdS_5 and examine the effects of perturbative higher derivative corrections on the ratio of shear viscosity to entropy density eta/s of the dual plasma. The structure of eta/s is controlled by…

High Energy Physics - Theory · Physics 2015-06-03 Sera Cremonini , Phillip Szepietowski

In this paper we investigate the ratio of shear viscosity to entropy density, $\eta/s$, in hyperscaling violating geometry with lattice structure. We show that the scaling relation with hyperscaling violation gives a strong constraint to…

High Energy Physics - Theory · Physics 2016-11-08 Yi Ling , Zhuo-Yu Xian , Zhenhua Zhou

Using the anti-de Sitter/conformal field theory correspondence, we relate the shear viscosity \eta of the finite-temperature N=4 supersymmetric Yang-Mills theory in the large N, strong-coupling regime with the absorption cross section of…

High Energy Physics - Theory · Physics 2010-02-18 G. Policastro , D. T. Son , A. O. Starinets

The correlation between the elliptic flow $v_2$ scaled by the impact parameter $b$ and the shear viscosity $\eta$ as well as the specific viscosity $\eta/s$, defined as the ratio of the shear viscosity to the entropy density $s$, is…

Nuclear Theory · Physics 2014-11-21 C. L. Zhou , Y. G. Ma , D. Q. Fang , G. Q. Zhang , J. Xu , X. G. Cao , W. Q. Shen

Using chiral perturbation theory we investigate the QCD shear viscosity ($\eta $) to entropy density ($s$) ratio below the deconfinement temperature ($\sim 170$ MeV) with zero baryon number density. It is found that $\eta /s$ of QCD is…

High Energy Physics - Phenomenology · Physics 2007-05-23 Eiji Nakano

Within a parton cascade approach we investigate the scaling of the differential elliptic flow $v_2(p_T)$ with eccentricity $\epsilon_x$ and system size and its sensitivity to finite shear viscosity. We present calculations for shear…

Nuclear Theory · Physics 2009-01-16 G. Ferini , M. Colonna , M. Di Toro , V. Greco

We show that in theories where the lowest energy excitations are not quasiparticles but they form a continuum, the shear viscosity to entropy density ratio goes to zero as the temperature goes to zero. In these theories therefore there is…

High Energy Physics - Theory · Physics 2009-03-04 A. Jakovac

We analyze the contributions of Nambu-Goldstone modes to the shear viscosity of a superfluid atomic Fermi gas close to unitarity. We show that the low temperature experimental values of the shear viscosity to entropy ratio, $\eta/s$, are…

Quantum Gases · Physics 2012-12-17 Massimo Mannarelli , Cristina Manuel , Laura Tolos

We investigate the collision energy dependence of shear viscosity over the entropy density ratio $\eta/s$ in Au+Au collisions at $\sqrt{s_{NN}}=19.6, 39$, and $62.4$ GeV, using Bayesian statistical analysis and Gaussian process emulators to…

Nuclear Theory · Physics 2016-10-04 Jussi Auvinen , Jonah E. Bernhard , Steffen A. Bass

We discuss a detailed study of the variation of shear viscosity, $\eta$, with temperature and baryon chemical potential within the framework of Polyakov$-$Nambu$-$Jona-Lasinio model. $\eta$ is found to depend strongly on the spectral width…

High Energy Physics - Phenomenology · Physics 2015-03-11 Sanjay K. Ghosh , Sibaji Raha , Rajarshi Ray , Kinkar Saha , Sudipa Upadhaya

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

Shear $\eta$ and bulk $\zeta$ viscosities are calculated in a quasiparticle model within a relaxation time approximation for pure gluon matter. Below $T_c$ the confined sector is described within a quasiparticle glueball model. Particular…

Nuclear Theory · Physics 2015-03-17 A. S. Khvorostukhin , V. D. Toneev , D. N. Voskresensky

I derive an exact integral expression for the ratio of shear viscosity over entropy density $\frac{\eta}{s}$ for the massless (critical) O(N) model at large N with quartic interactions. The calculation is set up and performed entirely from…

High Energy Physics - Theory · Physics 2021-12-23 Paul Romatschke

It was argued by Brigante et.al that the lower bound on the ratio of the shear viscosity to the entropy density in strongly coupled plasma is translated into microcausality violation in the dual gravitational description. Since transport…

High Energy Physics - Theory · Physics 2014-11-21 Alex Buchel , Sera Cremonini

Within a relaxation time approach using free nucleon-nucleon cross sections modified by the in-medium nucleon masses that are determined from an isospin- and momentum-dependent effective nucleon-nucleon interaction, we investigate the…

Nuclear Theory · Physics 2013-11-13 Jun Xu , Lie-Wen Chen , Che Ming Ko , Bao-An Li , Yu-Gang Ma

We calculate the partial electron shear viscosity $\eta_{ee}$ limited by electron-electron collisions in a strongly degenerate electron gas taking into account the Landau damping of transverse plasmons. The Landau damping strongly…

Astrophysics · Physics 2009-06-23 P. S. Shternin

We study the shear viscosity in an effective hydrodynamic theory and holographic model where the translational symmetry is broken by massless scalar fields. We identify the shear viscosity, $\eta$, from the coefficient of the shear tensor…

High Energy Physics - Theory · Physics 2016-11-09 Piyabut Burikham , Napat Poovuttikul

Transport coefficeints, in particular the shear viscosity to entropy density ratio is studied in systems where the small-width quasiparticle assumption is not valid. It is found that $\eta/s$ has no unversal lower bound, the minimal value…

High Energy Physics - Phenomenology · Physics 2017-08-23 A. Jakovac

We have calculated the shear viscosity coefficient $\eta$ of the strongly interacting matter in the relaxation time approximation, where a quasi particle description of quarks with its dynamical mass is considered from NJL model. Due to the…

Nuclear Theory · Physics 2013-12-31 Sabyasachi Ghosh , Anirban Lahiri , Sarbani Majumder , Rajarshi Ray , Sanjay K. Ghosh

In the Hartree approximation of Cornwall-Jackiw-Tomboulis (CJT) formalism of the real scalar field theory, we show that for the strongly coupled scalar system near phase transition, the shear viscosity over entropy density is small,…

High Energy Physics - Phenomenology · Physics 2010-01-15 Bao-Chun Li , Mei Huang