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Related papers: The Shear Viscosity in Anisotropic Phases

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We investigate the behavior of shear viscosity in the presence of small anisotropy and a finite chemical potential. First, we construct an anisotropic Reissner Nordstr{\"o}m blackbrane in 5 dimensions in a simple Einstein-Maxwell theory…

High Energy Physics - Theory · Physics 2017-06-07 Soumangsu Chakraborty , Rickmoy Samanta

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 consider a system consisting of a strongly interacting, ultracold unitary Fermi gas under harmonic confinement. Our analysis suggests the possibility of experimentally studying, in this system, an anisotropic shear viscosity tensor…

Quantum Gases · Physics 2017-11-08 Rickmoy Samanta , Rishi Sharma , Sandip P. Trivedi

We present a proposal to measure anisotropic shear viscosity in a strongly interacting, ultra-cold, unitary Fermi gas confined in a harmonic trap. We introduce anisotropy in this setup by strongly confining the gas in one of the directions…

Quantum Gases · Physics 2017-03-27 Rickmoy Samanta , Rishi Sharma , Sandip P. Trivedi

The shear viscosity to the entropy density ratio $\eta/s$ of the anisotropic superfluid has been calculated by means of the gauge/gravity duality in the presence of the {\it dark matter} sector. The {\it dark matter} has been described by…

High Energy Physics - Theory · Physics 2017-07-26 Marek Rogatko , Karol I. Wysokinski

We consider a system consisting of $5$ dimensional gravity with a negative cosmological constant coupled to a massless scalar, the dilaton. We construct a black brane solution which arises when the dilaton satisfies linearly varying…

High Energy Physics - Theory · Physics 2015-01-14 Sachin Jain , Nilay Kundu , Kallol Sen , Aninda Sinha , Sandip P. Trivedi

We consider asymptotically-AdS $n$-dimensional black brane solutions in a theory of gravity coupled to a set of $N$ $p$-form field strengths, in which the field strengths carry magnetic charges. For appropriately chosen charges, the metrics…

High Energy Physics - Theory · Physics 2017-02-01 Hai-Shan Liu , H. Lu , C. N. Pope

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, 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

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

In this paper, we introduced the black brane solution in Rastall theory and in the context of massive gravity. The ratio of shear viscosity to entropy density is calculated for this solution. Our result shows that the KSS bound violates for…

High Energy Physics - Theory · Physics 2018-10-29 Mehdi Sadeghi

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 argue that the Kovtun--Son--Starinets (KSS) lower bound on the viscosity to entropy density ratio holds in fluid systems but is violated in solid materials with a non-zero shear elastic modulus. We construct explicit examples of this by…

High Energy Physics - Theory · Physics 2017-01-13 Lasma Alberte , Matteo Baggioli , Oriol Pujolas

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

The ratio of shear viscosity to entropy density, $\eta/s$, is computed in various holographic geometries that break translation invariance (but are isotropic). The shear viscosity does not have a hydrodynamic interpretation in such…

High Energy Physics - Theory · Physics 2016-04-20 Sean A. Hartnoll , David M. Ramirez , Jorge E. Santos

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

We investigate black brane solutions in asymptotically Lifshitz spacetime in 3+1-dimensional Horndeski gravity, which admit a critical exponent fixed at $z=1/2$. The cosmological constant depends on $z$ as $\Lambda=-(1+2z)/L^{2}$. We…

High Energy Physics - Theory · Physics 2020-04-06 F. A. Brito , F. F. Santos

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

In this paper, the Einstein AdS black brane solution in the presence of a string cloud in the context of d-dimensional massive gravity is introduced. The ratio of shear viscosity to entropy density for this solution violates the KSS bound…

High Energy Physics - Theory · Physics 2020-11-05 Mehdi Sadeghi

It has been known that a non-perfect fluid that accounts for dissipative viscous effects can evade a highly anisotropic chaotic mixmaster approach to a singularity. Viscosity is often simply parameterised in this context, so it remains…

General Relativity and Quantum Cosmology · Physics 2022-02-02 Chandrima Ganguly , Jerome Quintin
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