Related papers: $\eta/s$ at finite coupling
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.…
The ratio of shear viscosity ($\eta$) to entropy density ($s$) for an equilibrated system is investigated in intermediate energy heavy ion collisions below 100$A$ MeV within the framework of the Boltzmann-Uehling-Uhlenbeck (BUU) model .…
In an isotropic strongly interacting quantum liquid without quasiparticles, general scaling arguments imply that the dimensionless ratio $(k_B /\hbar)\, \eta/s$, where $\eta$ is the shear viscosity and $s$ is the entropy density, is a…
The ratio of the shear viscosity ($\eta$) to entropy density ($s$) for the intermediate energy heavy-ion collisions has been calculated by using the Green-Kubo method in the framework of the quantum molecular dynamics model. The theoretical…
The correlation between the elliptic flow $v_2$ scaled by the impact parameter $b$ and the shear viscosity $\eta$ as well as the specific viscosity $\eta/s$, defined as the ratio of the shear viscosity to the entropy density $s$, is…
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…
We investigate the collision energy dependence of shear viscosity over the entropy density ratio $\eta/s$ in Au+Au collisions at $\sqrt{s_{NN}}=19.6, 39$, and $62.4$ GeV, using Bayesian statistical analysis and Gaussian process emulators to…
The shear viscosity to entropy ratio ($\eta/s$) is estimated for the hot and dense QCD matter created in Au+Au collisions at RHIC ($\sqrt{s_{NN}}=200$ GeV). A very low value is found $\eta/s \sim 0.1$, which is close to the conjectured…
In the present paper, based on the principles of gauge/gravity duality we analytically compute the shear viscosity to entropy ratio corresponding to the superfluid phase in Einstein Gauss-Bonnet gravity. From our analysis we note that the…
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…
We study the shear viscosity in an effective hydrodynamic theory and holographic model where the translational symmetry is broken by massless scalar fields. We identify the shear viscosity, $\eta$, from the coefficient of the shear tensor…
We study the ratio of the shear viscosity to the entropy density for various holographic superfluids. For the s-wave case, the ratio has the universal value 1/(4pi) as in various holographic models. For the p-wave case, there are two shear…
Nuclear multifragmentation in intermediate energy heavy ion collisions has long been associated with liquid-gas phase transition. We calculate the shear viscosity to entropy density ratio eta/s for an equilibrated system of nucleons and…
Shear viscosity $\eta$ is calculated for the nuclear matter described as a system of interacting nucleons with the van der Waals (VDW) equation of state. The Boltzmann-Vlasov kinetic equation is solved in terms of the plane waves of the…
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…
We investigate the shear viscosity $\eta$ and the entropy density $s$ of strongly coupled $\mathcal{N}=4$ super Yang-Mills (SYM) plasma in late time of hydrodynamic evolution with AdS/CFT duality and Bjorken scaling. We use correlation…
The shear viscosity, eta, of a fermi gas with non-relativistic conformal symmetry in two spatial dimensions is investigated. We find that eta/s, s being the entropy density, diverges as a gas of free particles in this system. It is in…
We calculate the ratio eta/s, the shear viscosity (eta) to entropy density (s), which characterizes how perfect a fluid is, in weakly coupled real scalar field theories with different types of phase transitions. The mean-field results of…
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…
The shear viscosity of a two-dimensional (2D) liquid was calculated using equilibrium molecular dynamics simulations with a Yukawa potential. The shear viscosity has a minimum, at a Coulomb coupling parameter of about 17, arising from the…