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Related papers: Viscosity of $R^2$ Modified AdS Black Brane

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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 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 explore a modified black brane within AdS spacetime, characterized by the Lagrangian density $\frac{1}{q} \text{arcsin}(qR)-2\Lambda$. Due to the absence of an analytic solution, we approach the Einstein equations using a…

High Energy Physics - Theory · Physics 2024-10-29 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

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

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

The Einstein AdS black brane with a cloud of strings background in context of massive gravity is introduced. There is a momentum dissipation on the boundary because of graviton mass on the bulk. The ratio of shear viscosity to entropy…

High Energy Physics - Theory · Physics 2019-09-23 Mehdi Sadeghi , Hadi Ranjbari

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 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 calculate the ratio of shear viscosity to entropy density for a black brane of $5$-dimensional Einstein-Yang-Mills Gravity by Kubo and membrane paradigm methods. The former gives $\frac{1}{4\pi}$ exactly which is an expected result in…

High Energy Physics - Theory · Physics 2015-08-11 Mehdi Sadeghi , Shahrokh Parvizi

We present new rotating black brane solutions which solve Einstein's equations with cosmological constant $\Lambda$ in arbitrary dimension $d$. For negative $\Lambda$, the branes naturally appear in AdS supergravity compactifications, and…

High Energy Physics - Theory · Physics 2010-02-03 Dietmar Klemm

In this paper, a non-abelian $arcsin$-Yang-Mills AdS black brane solution is introduced. Then, the color non-abelian direct current (DC) conductivity and shear viscosity to entropy density ratio of this model is calculated using…

High Energy Physics - Theory · Physics 2023-09-12 Mehdi Sadeghi , S. M. Moosavi Khansari

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 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

We investigate static, planar, solutions of Einstein-scalar gravity admitting an anti-de Sitter (AdS) vacuum. When the squared mass of the scalar field is positive and the scalar potential can be derived from a superpotential, minimum…

High Energy Physics - Theory · Physics 2013-05-30 Mariano Cadoni , Salvatore Mignemi , Matteo Serra

A family of deformed AdS$_5$-Schwarzschild black branes is here derived, employing the membrane paradigm of AdS/CFT. The solution of the Einstein-Hilbert action, with the Gibbons-Hawking term and a counter-term that eliminates eventual…

High Energy Physics - Theory · Physics 2020-06-15 A. J. Ferreira-Martins , P. Meert , R. da Rocha

We construct anisotropic black brane solutions and analyse the behaviour of some of their metric perturbations. These solutions correspond to field theory duals in which rotational symmetry is broken due an externally applied, spatially…

High Energy Physics - Theory · Physics 2022-11-21 Sachin Jain , Rickmoy Samanta , Sandip P. Trivedi

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 paper, we study the holographic dual to an asymptotically anti-de Sitter black brane in an Einstein-Yang-Mills model with a non-minimal coupling between the Riemann and Yang-Mills fields. First, we construct a planar black hole…

High Energy Physics - Theory · Physics 2023-08-16 Mehdi Sadeghi

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
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