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Shear viscosity measures the amount of internal friction in a simple fluid. In kinetic theory shear viscosity is related to momentum transport by quasi-particles, and the uncertainty relation implies that the ratio of shear viscosity eta to…

Fluid Dynamics · Physics 2010-01-15 Thomas Schaefer

We investigate the thermodynamical behavior and the scaling symmetries of the scalar dressed black brane (BB) solutions of a recently proposed, exactly integrable Einstein-scalar gravity model [1], which also arises as compactification of…

High Energy Physics - Theory · Physics 2015-06-05 Mariano Cadoni , Salvatore Mignemi

The universal lower bound of the ratio of shear viscosity to entropy density is suggested by the string theory and gauge duality for any matter. We examined the ratio of shear viscosity to entropy density for viscous accretion flow towards…

General Relativity and Quantum Cosmology · Physics 2019-06-28 Sandip Dutta , Ritabrata Biswas

We compute the dimensionality dependence of $\eta/s$ for charged black branes with Gauss-Bonnet correction. We find that both causality and stability constrain the value of Gauss-Bonnet coupling constant to be bounded by 1/4 in the infinite…

High Energy Physics - Theory · Physics 2014-11-18 Xian-Hui Ge , Sang-Jin Sin

The ratio of shear viscosity to entropy density $\eta/s$ of any material in nature has been conjectured to have a lower bound of $1/4\pi$, the famous KSS bound. We examine string theory models for evidence in favour of and against this…

High Energy Physics - Theory · Physics 2009-11-18 Aninda Sinha , Robert C. Myers

We have examined holographic renormalization group($RG$) flows of the shear viscosities in anisotropic holographic superfluids via their gravity duals, Einstein-SU(2) Yang-Mills system. In anisotropic phase, below the critical temperature…

High Energy Physics - Theory · Physics 2012-06-27 Jae-Hyuk Oh

We investigate $\eta/s$ in linear scalar fields modified Gauss-Bonnet theory that breaks translation invariance. We first calculate $\eta/s$ both analytically and numerically and show its relationship with temperature in log-log plot. Our…

High Energy Physics - Theory · Physics 2016-09-28 Yi-Li Wang , Xian-Hui Ge

We study electrically charged asymptotically flat black brane solutions whose world-volume fields are slowly varying with the coordinates. Using familiar techniques, we compute the transport coefficients of the fluid dynamic derivative…

High Energy Physics - Theory · Physics 2013-11-11 Jakob Gath , Andreas Vigand Pedersen

Using the non-relativistic hydrodynamic expansion, we solve equations of motion for Einstein gravity and Gauss-Bonnet gravity with a negative cosmological constant within the region between a finite cutoff surface and a black brane horizon,…

High Energy Physics - Theory · Physics 2011-07-21 Rong-Gen Cai , Li Li , Yun-Long Zhang

We develop a model of an electrorheological fluid such that the fluid is considered as an anisotropic one with the viscosity depending on the second invariant of the rate of strain tensor, on the module of the vector of electric field…

Mathematical Physics · Physics 2007-05-23 R. H. W. Hoppe , W. G. Litvinov

In this paper we generalize the construction of locally boosted black brane space time to higher derivative gravities. We consider the Gauss-Bonnet term (with coefficient $\alpha'$) as a toy example. We find the solution to the $\alpha'$…

High Energy Physics - Theory · Physics 2014-11-18 Suvankar Dutta

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

We consider Lovelock theories of gravity in the context of AdS/CFT. We show that, for these theories, causality violation on a black hole background can occur well in the interior of the geometry, thus posing more stringent constraints than…

High Energy Physics - Theory · Physics 2011-06-07 Xian O. Camanho , Jose D. Edelstein , Miguel F. Paulos

This paper is concerned with an initial and boundary value problem of the one-dimensional planar MHD equations for viscous, heat-conducting, compressible, ideal polytropic fluids with constant transport coefficients and large data. The…

Analysis of PDEs · Mathematics 2020-02-19 Xia Ye , Jianwen Zhang

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

We investigate the relation between mobility and diffusivity for Brownian particles under steady shear near the glass transition, using mode coupling approximations. For the two directions perpendicular to the shear direction, the particle…

Soft Condensed Matter · Physics 2009-11-10 Matthias Krüger , Matthias Fuchs

String theory and gauge/gravity duality suggest the lower bound of shear viscosity (eta) to entropy density (s) for any matter to be ~ mu hbar/4pi k_B, when hbar and k_B are reduced Planck and Boltzmann constants respectively and mu <= 1.…

High Energy Astrophysical Phenomena · Physics 2013-04-01 Banibrata Mukhopadhyay

We interpret as shear viscosity the anisotropic pressure that emerges in inhomogeneous spherically symmetric spacetimes described by the Lemaitre-Tolman-Bondi (LTB) metric in a comoving frame. By assuming that local isotropic pressure and…

General Relativity and Quantum Cosmology · Physics 2008-12-24 Roberto A Sussman

Kovtun, Son and Starinets have conjectured that the viscosity to entropy density ratio $\eta/s$ is always bounded from below by a universal multiple of $\hbar$ i.e., $\hbar/(4\pi k_{B})$ for all forms of matter. Mysteriously, the proposed…

High Energy Physics - Theory · Physics 2009-11-11 Omid Saremi

In this work, we investigate the shear elasticity and the shear viscosity in a simple holographic axion model with broken translational symmetry and rotational symmetry in space via the perturbation computation. We find that, in the case of…

High Energy Physics - Theory · Physics 2025-03-31 Lei Li , Wei-Jia Li , Xiao-Mei Kuang