English
Related papers

Related papers: Shear Viscosity to Entropy Density for a Black Bra…

200 papers

We introduce the Einstein-Yang-Mills AdS black brane solution in context of massive gravity. The ratio of shear viscosity to entropy density is calculated for this solution. This value violates the KSS bound if we apply the Dirichlet…

High Energy Physics - Theory · Physics 2018-11-01 Mehdi Sadeghi

In this paper we calculate the ratio of transverse shear viscosity to entropy density for the general anisotropic black brane in Horava-Lifshitz gravity. There is a well-known conjecture that states this ratio should be larger than…

High Energy Physics - Theory · Physics 2019-06-27 Mehdi Sadeghi

We construct the membrane paradigm for black objects in Einstein-Gauss-Bonnet gravity in spacetime dimensions $ \ge 5$. As in the case of general relativity, the horizon can be modeled as a membrane endowed with fluidlike properties. We…

General Relativity and Quantum Cosmology · Physics 2017-04-17 Ted Jacobson , Arif Mohd , Sudipta Sarkar

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

The ratio of the shear viscosity to the entropy density is calculated for non-extremal Gauss-Bonnet (GB) black holes coupled to Born-Infeld (BI) electrodynamics in $5$ dimensions. The result is found to get corrections from the BI parameter…

High Energy Physics - Theory · Physics 2017-09-19 Saurav Das , Sunandan Gangopadhyay , Debabrata Ghorai

The ratio of shear viscosity to volume density of entropy can be used to characterize how close a given fluid is to being perfect. Using string theory methods, we show that this ratio is equal to a universal value of $\hbar/4\pi k_B$ for a…

High Energy Physics - Theory · Physics 2007-05-23 P. Kovtun , D. T. Son , A. O. Starinets

We revisit the membrane paradigm calculations of the holographic shear viscosity tensor of strongly coupled isotropic plasmas with Einstein gravity dual by emphasizing the fact which was overlooked in the previous literatures that the shear…

High Energy Physics - Theory · Physics 2013-06-07 Kiminad A. Mamo

In this paper we consider a metric with hyperscaling violation on black brane background. In this background we calculate the ratio of shear viscosity to entropy density with hydrodynamics information. The calculation of this quantity lead…

High Energy Physics - Theory · Physics 2015-06-19 Jafar Sadeghi , Ali Asadi

We investigate the Einstein-Hilbert black brane solution in four-dimensional Anti-de Sitter (AdS) spacetime supplemented by a quadratic Ricci scalar term $q L^2 R^2$, where $q$ is a dimensionless coupling constant and $L$ is the AdS radius.…

High Energy Physics - Theory · Physics 2026-02-06 Razieh Golmoradifard , Mehdi Sadeghi , Behrooz Malekolkalami

Near the horizon of a black brane solution in Anti-de Sitter space, the long-wavelength fluctuations of the metric exhibit hydrodynamic behaviour. For Einstein's theory, the ratio of the shear viscosity of near-horizon metric fluctuations…

High Energy Physics - Theory · Physics 2009-01-21 Ram Brustein , A. J. M. Medved

A black brane solution to a Gauss-Bonnet massive gravity is introduced. In the context of AdS/CFT correspondence, the viscosity to entropy ratio is found by the Green-Kubo formula. The result indicates violation of the well-known KSS bound…

High Energy Physics - Theory · Physics 2016-01-27 Mehdi Sadeghi , Shahrokh Parvizi

In this paper, AdS black brane solution of Einstein-Hilbert gravity with non-abelian exponential guage theory of Yang-Mills type is introduced. DC conductivity and the ratio of shear viscosity to entropy density as two important transport…

High Energy Physics - Theory · Physics 2024-07-09 Mehdi Sadeghi , Faramaz Rahmani

In this paper, the Einstein AdS black brane solution in the presence of quintessence in context of massive gravity is introduced. The ratio of shear viscosity to entropy density for this solution violates the KSS bound by applying the…

High Energy Physics - Theory · Physics 2021-09-20 Mehdi Sadeghi

We calculate the ratio of shear viscosity to entropy density for charged black branes in third order Lovelock theory. For chargeless black branes, the result turns out to be consistent with the prediction made in $\rm arXiv:0808.3498[\rm…

High Energy Physics - Theory · Physics 2009-11-17 Xian-Hui Ge , Sang-Jin Sin , Shao-Feng Wu , Guo-Hong Yang

Motivated by the vast string landscape, we consider the shear viscosity to entropy density ratio in conformal field theories dual to Einstein gravity with curvature square corrections. After field redefinitions these theories reduce to…

High Energy Physics - Theory · Physics 2010-04-06 Mauro Brigante , Hong Liu , Robert C. Myers , Stephen Shenker , Sho Yaida

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 extract the shear viscosity to entropy density ratio \eta/s of cold fermionic atoms in the unitarity limit from experimental data on the damping of collective excitations. We find that near the critical temperature \eta/s is roughly…

Other Condensed Matter · Physics 2008-11-26 Thomas Schaefer

The well known shear viscosity to entropy density ratio ($\eta /s$) cannot be computed when the black hole space-time has zero thermodynamic entropy. This is the case, for example, when General Relativity in four dimensions is complemented…

High Energy Physics - Theory · Physics 2023-05-24 Moisés Bravo-Gaete , Luis Guajardo , Fabiano F. Santos

The weak gravity conjecture and the shear viscosity to entropy density bound place constraints on low energy effective field theories that may help to distinguish which theories can be UV completed. Recently, there have been suggestions of…

High Energy Physics - Theory · Physics 2010-12-14 Aaron J. Amsel , Dan Gorbonos

The Green-Kubo relation and fluctuation-dissipation theorem are employed to calculate the shear viscosity $\eta$ of a finite hot nucleus directly from the width and energy of the giant dipole resonance (GDR) of this nucleus. The ratio…

Nuclear Theory · Physics 2015-05-30 Nguyen Dinh Dang
‹ Prev 1 2 3 10 Next ›