相关论文: The Quantum Viscosity Bound In Lovelock Gravity
We explore the constraints imposed on higher curvature corrections of the Lovelock type due to causality restrictions in the boundary of asymptotically AdS space-time. In the framework of AdS/CFT, this is related to positivity of the energy…
We reconsider, from a novel perspective, how unitarity constrains the corrections to the ratio of shear viscosity \eta\ to entropy density s. We start with higher-derivative extensions of Einstein gravity in asymptotically anti-de Sitter…
We study finite temperature transport in the Luttinger-Abrikosov-Beneslavskii phase -- an interacting, scale invariant, non-Fermi liquid phase found in quadratic semimetals. We develop a kinetic equation formalism to describe the d.c.…
We calculate the shear viscosity in the frame of AdS/CFT correspondence for the field theory with a gravity dual of Einstein-Born-Infeld gravity. We find that the ratio of $\eta/s$ is still the conjectured universal value $1/4\pi$ at least…
There have been a number of forms of a conjecture that there is a universal lower bound on the ratio, eta/s, of the shear viscosity, eta, to entropy density, s, with several different domains of validity. We examine the various forms of the…
We study quantum corrections at one-loop order to the shear viscosity to entropy ratio by implementing the Vilkovisky-Barvinsky effective action in asymptotically Anti-de Sitter spacetimes. The shear viscosity is shown to receive no…
In recent work we showed that, for a class of conformal field theories (CFT) with Gauss-Bonnet gravity dual, the shear viscosity to entropy density ratio, $\eta/s$, could violate the conjectured Kovtun-Starinets-Son viscosity bound,…
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…
We calculate the shear viscosity of strongly coupled field theories dual to Gauss-Bonnet gravity at zero temperature with nonzero chemical potential. We find that the ratio of the shear viscosity over the entropy density is $1/4\pi$, which…
It was argued by Brigante et.al that the lower bound on the ratio of the shear viscosity to the entropy density in strongly coupled plasma is translated into microcausality violation in the dual gravitational description. Since transport…
We calculate shear viscosity to entropy density ratio in presence of four derivative (with coefficient $\alpha'$) and six derivative (with coefficient $\alpha'^2$) terms in bulk action. In general, there can be three possible four…
We investigate the low-temperature behavior of the ratio between the shear viscosity \eta and the entropy density s in the unitary Fermi gas by using a model based on the zero-temperature spectra of both bosonic collective modes and…
We investigate general features of charged Lovelock black branes by giving a detailed description of geometrical, thermodynamic and holographic properties of charged Gauss-Bonnet (GB) black branes in five dimensions. We show that when…
It was recently conjectured that the ratio of the shear viscosity to entropy density, $ \eta/ s$, for any fluid always exceeds $\hbar/(4 \pi k_B)$. This conjecture was motivated by quantum field theoretic results obtained via the AdS/CFT…
We use the real-time finite-temperature AdS/CFT correspondence to compute the effect of general R^2 corrections to the gravitational action in AdS space on the shear viscosity of the dual gauge theory. The R^2 terms in AdS_5 are determined…
It has been conjectured, on the basis of the gauge-gravity duality, that the ratio of the shear viscosity to the entropy density should be universally bounded from below by 1/ 4 pi in units of the Planck constant divided by the Boltzmann…
This review highlights some of the lessons that the holographic gauge/gravity duality has taught us regarding the behavior of the shear viscosity to entropy density in strongly coupled field theories. The viscosity to entropy ratio has been…
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…
We present the first ab initio determination of the shear viscosity eta of the Unitary Fermi Gas, based on finite temperature quantum Monte Carlo calculations and the Kubo linear-response formalism. We determine the temperature dependence…
Starting from relativistic quantum field theories, Kovtun et al. (2005) have quite recently proposed a lower bound eta/s >= hbar /(4 pi kB), where eta is the shear viscosity and s the volume density of entropy for dense liquids. If their…