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Related papers: Minimum Shear Viscosity over Entropy Density at Ph…

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We study the shear and bulk viscosities of partonic and hadronic matter - as well as the electric conductivity - as functions of temperature $T$ within the Parton-Hadron-String Dynamics (PHSD) off-shell transport approach. Dynamical…

Nuclear Theory · Physics 2015-06-15 E. L. Bratkovskaya , V. Ozvenchuk , W. Cassing , V. P. Konchakovski , O. Linnyk

We study whether it is possible to use high-$p_\perp$ data/theory to constrain the temperature dependence of the shear viscosity over entropy density ratio $\eta/s$ of the matter formed in ultrarelativistic heavy-ion collisions at the BNL…

High Energy Physics - Phenomenology · Physics 2023-11-14 Bithika Karmakar , Dusan Zigic , Igor Salom , Jussi Auvinen , Pasi Huovinen , Marko Djordjevic , Magdalena Djordjevic

The pressure and the viscosity in two-dimensional sheared granular assemblies are investigated numerically. The behavior of both pressure and viscosity is smoothly changing qualitatively when starting from a mono-disperse hard-disk system…

Statistical Mechanics · Physics 2010-07-20 Michio Otsuki , Hisao Hayakawa , Stefan Luding

Based on the finite-temperature AdS/CFT correspondence, we calculate the ratio of shear viscosity to entropy density in any Lovelock theories to any order. Our result shows that any Lovelock correction terms except the Gauss-Bonnet term…

High Energy Physics - Theory · Physics 2010-04-30 Fu-Wen Shu

The shear viscosity $\eta$ has been calculated by using the Green-Kubo relation in the framework of a partonic transport approach solved at cascade level. We compare the numerical results for $\eta$ obtained from the Green-Kubo correlator…

Nuclear Theory · Physics 2015-09-01 S. Plumari , A. Puglisi , F. Scardina , V. Greco

We consider classes of translationally invariant black hole solutions whose equations of state closely resemble that of QCD at zero chemical potential. We use these backgrounds to compute the ratio zeta/s of bulk viscosity to entropy…

High Energy Physics - Theory · Physics 2008-11-26 Steven S. Gubser , Abhinav Nellore , Silviu S. Pufu , Fabio D. Rocha

We revisit the computation of the shear viscosity to entropy ratio in a holographic p-wave superfluid model, focusing on the role of rotational symmetry breaking. We study the interplay between explicit and spontaneous symmetry breaking and…

High Energy Physics - Theory · Physics 2023-07-06 Matteo Baggioli , Sera Cremonini , Laura Early , Li Li , Hao-Tian Sun

We show that the generalized second law of thermodynamics may shed much light on the mysterious Kovtun-Son-Starinets (KSS) bound on the ratio of viscosity to entropy density. In particular, we obtain the lower bound $\eta/s…

High Energy Physics - Theory · Physics 2009-10-12 Shahar Hod

We evaluate the ratio of shear viscosity to entropy density in a pion gas employing the Uehling-Uehlenbeck equation and experimental phase-shifts parameterized by means of the SU(2) Inverse Amplitude Method. We find that the ratio for this…

High Energy Physics - Phenomenology · Physics 2008-11-26 Antonio Dobado , Felipe J. Llanes-Estrada

Dielectric relaxation measurements on supercooled triphenyl phosphite show that at low temperatures time-temperature superposition (TTS) is accurately obeyed for the primary (alpha) relaxation process. Measurements on 6 other molecular…

Soft Condensed Matter · Physics 2009-10-31 Niels Boye Olsen , Tage Christensen , Jeppe C. Dyre

Athermal (i.e. zero-temperature) under-constrained systems are typically floppy, but they can be rigidified by the application of external strain, which is theoretically well understood. Here and in the companion paper, we extend this…

Soft Condensed Matter · Physics 2024-12-31 Cheng-Tai Lee , Matthias Merkel

The behavior of viscosity, $\eta$, as a function of concentration in dense fluids remains an unsolved problem, as is the case with other transport coefficients. Boltzmann's theory and the Chapman-Enskog method predict the value of the…

Statistical Mechanics · Physics 2025-07-14 L. Marchioni , M. A. Di Muro , M. Hoyuelos

Although realizing wetting transitions of droplets spontaneously on solid rough surfaces is quite challenging, it is becoming a key research topic in many practical applications which require highly efficient removal of liquid. We report…

Soft Condensed Matter · Physics 2015-06-30 Cunjing Lv , Pengfei Hao , Xiwen Zhang , Feng He

We address a discrepancy between different computations of $\eta/s$ (shear viscosity over entropy density) of hadronic matter. Substantial deviations of this coefficient are found between transport approaches mainly based on resonance…

Nuclear Theory · Physics 2018-05-16 J. -B. Rose , J. M. Torres-Rincon , A. Schäfer , D. R. Oliinychenko , H. Petersen

The relation between the specific shear viscosity $\eta/s$ and the dimensionless jet quenching parameter $\hat{q}/T^3$ in perturbative QCD is explored at next-to-leading order in the coupling constant. It is shown that the relation changes…

High Energy Physics - Phenomenology · Physics 2021-10-13 Berndt Müller

This is a response to the comment, arXiv:0709.4651. It is noted that while the comment raises an extremely interesting and subtle point, the original conclusion that theoretically consistent exceptions exist for the proposed general bound…

High Energy Physics - Theory · Physics 2007-11-19 Thomas D. Cohen

We calculate the shear viscosity of strongly coupled field theories dual to Gauss-Bonnet gravity at zero temperature with nonzero chemical potential. We find that the ratio of the shear viscosity over the entropy density is $1/4\pi$, which…

High Energy Physics - Theory · Physics 2010-05-12 Rong-Gen Cai , Yan Liu , Ya-Wen Sun

We calculate the shear viscosity over entropy density ratio $\eta/s$ in Yang--Mills theory from the Kubo formula using an exact diagrammatic representation in terms of full propagators and vertices using gluon spectral functions as external…

High Energy Physics - Phenomenology · Physics 2015-09-16 Nicolai Christiansen , Michael Haas , Jan M. Pawlowski , Nils Strodthoff

We investigate temperature dependent behavior of various transport coefficients in a dynamical holographical QCD model. We show the nontrivial temperature dependent behavior of the transport coefficients, like bulk viscosity, electric…

High Energy Physics - Phenomenology · Physics 2014-11-20 Danning Li , Song He , Mei Huang

The shear viscosity is calculated by means of the perturbative kinetic partonic cascade BAMPS with CGC initial conditons for various saturation momentum scale Q_s. eta/s ~ 0.15 stays approximately constant when going from RHIC to LHC.

High Energy Physics - Phenomenology · Physics 2007-06-29 A. El , C. Greiner , Z. Xu