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Related papers: The Shear Viscosity in Anisotropic Phases

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We analyse near-extremal black brane configurations in asymptotically $\mathrm{AdS}_4$ spacetime with the temperature $T$, chemical potential $\mu$, and three-velocity $u^\nu$, varying slowly. We consider a low-temperature limit where the…

High Energy Physics - Theory · Physics 2021-02-26 Upamanyu Moitra , Sunil Kumar Sake , Sandip P. Trivedi

Besides expanding anisotropically, the universe can also be anisotropic at the level of its (spatial) curvature. In particular, models with anisotropic curvature and isotropic expansion leads both to a $\Lambda$CDM-like phenomenology and to…

General Relativity and Quantum Cosmology · Physics 2017-11-17 Felipe O. Franco , Thiago S. Pereira

We study dynamical condensation process in a holographic superconductor model with anisotropy. The time-dependent numerical solution is constructed for the Einstein-Maxwell-dilaton theory with complex scalar in asymptotic AdS spacetime. The…

High Energy Physics - Theory · Physics 2014-09-17 Xiaojian Bai , Bum-Hoon Lee , Miok Park , Khimphun Sunly

Measured 2nd and 4th azimuthal anisotropy coefficients v_{2,4}(N_{part}), p_T) are scaled with the initial eccentricity \varepsilon_{2,4}(N_{part}) of the collision zone and studied as a function of the number of participants N_{part} and…

A family of spherically symmetric solutions with horizon in the model with multi-component anisotropic fluid (MCAF) is obtained. The metric of any solution contains n-1 Ricci-flat ``internal space'' metrics and for certain equations of…

High Energy Physics - Theory · Physics 2007-05-23 V. D. Ivashchuk , V. N. Melnikov , A. B. Selivanov

According to the gauge-gravity duality, we systematically study the Schwinger effect and electric instability with anisotropy in a top-down holographic approach. The anisotropic black brane and bubble (soliton) background in IIB…

High Energy Physics - Theory · Physics 2022-08-23 Si-wen Li , Sen-kai Luo , Hao-qian Li

A viscous instability in shearing laminar axisymmetric hydrodynamic flows around a gravitating center is described. In the linearized hydrodynamic equations written in the Boussinesq approximation with microscopic molecular transport…

High Energy Astrophysical Phenomena · Physics 2015-03-18 Nikolai Shakura , Konstantin Postnov

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

The gravity/gauge theory duality has provided us a way of studying QCD at short distances from straightforward calculations in classical general relativity. Among numerous results obtained so far, one of the most striking is the…

General Relativity and Quantum Cosmology · Physics 2011-02-16 Ishwaree P Neupane

We investigate the black hole solutions in the $R^2$-gravity, where the action contains the square of the curvature. In case that the action does not contain the square of the Riemann tensor and in case that the $R^2$-terms are the…

High Energy Physics - Theory · Physics 2007-05-23 Shin'ichi Nojiri

We study long wavelength perturbations of neutral black p-branes in asymptotically flat space and show that, as anticipated in the blackfold approach, solutions of the relativistic hydrodynamic equations for an effective p+1-dimensional…

High Energy Physics - Theory · Physics 2014-11-20 Joan Camps , Roberto Emparan , Nidal Haddad

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

We obtain the entropy of a homogeneous anisotropic universe applicable, by assumption, to the fractional branes in the universe in the model of Chowdhury and Mathur. The entropy for the 3 or 4 charge fractional branes thus obtained is not…

High Energy Physics - Theory · Physics 2008-11-26 S. Kalyana Rama

The ratio eta/s, shear viscosity (eta) to entropy density (s), reaches its local minimum at the (second order) phase transition temperature in a wide class of systems. It was suspected that this behavior might be universal. However, a…

High Energy Physics - Phenomenology · Physics 2011-06-28 Jiunn-Wei Chen , Chang-Tse Hsieh , Han-Hsin Lin

A Bianchi type -I metric of Kasner form is considered, when the space is filled with a viscous fluid. Whereas an ideal (nonviscous) fluid permits the Kasner metric to be anisotropic provided that the fluid satisfies the Zel'dovich equation…

General Relativity and Quantum Cosmology · Physics 2009-01-14 I. Brevik , S. V. Pettersen

This paper gives a theoretical analysis for the fundamental problem of anisotropy induced by shear forces onan adhesive contact, discussing the experimental data of the companion Letter. We present a fracture mechanicsmodel where two…

Soft Condensed Matter · Physics 2019-06-10 A. Papangelo , J. Scheibert , R. Sahli , G. Pallares , M. Ciavarella

This work develops a computational and theoretical framework for determining effective permeabilities in anisotropic microscopic geometries containing dense, fibre-like obstacles, motivated by the need to model flow in coiled aneurysm…

Using the gauge/gravity duality we study the imaginary part of the static potential associated to the thermal width in finite temperature strongly coupled anisotropic plasma. We firstly derive the potential for a generic anisotropic…

High Energy Physics - Theory · Physics 2013-12-03 Kazem Bitaghsir Fadafan , Dimitrios Giataganas , Hesam Soltanpanahi

The loading of a granular material induces anisotropies of the particle arrangement (fabric) and of the material's strength, incremental stiffness, and permeability. Thirteen measures of fabric anisotropy are developed, which are arranged…

Soft Condensed Matter · Physics 2018-12-21 Matthew R. Kuhn , WaiChing Sun , Qi Wang

A family of spherically symmetric solutions in the model with 1-component anisotropic fluid is considered. The metric of the solution depends on a parameter q > 0 relating radial pressure and the density and contains n -1 parameters…

General Relativity and Quantum Cosmology · Physics 2007-05-23 H. Dehnen , V. D. Ivashchuk , V. N. Melnikov