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Related papers: Shear viscosity in superfluid neutron stars

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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…

Nuclear Theory · Physics 2014-11-21 C. L. Zhou , Y. G. Ma , D. Q. Fang , G. Q. Zhang , J. Xu , X. G. Cao , W. Q. Shen

We experimentally investigate shear thickening in dense granular suspensions under oscillatory shear. Directly imaging the suspension-air interface, we observe dilation beyond a critical strain $\gamma_c$ and the end of shear thickening as…

Soft Condensed Matter · Physics 2014-10-14 Qin Xu , Sayantan Majumdar , Eric Brown , Heinrich M. Jaeger

Models of neutron stars (NSs) with hyperon cores are constructed with an effective chiral model in mean-field approximation. The hyperon couplings are fixed by reproducing their experimentally determined binding energies. The impact of…

Nuclear Theory · Physics 2019-01-31 Debashree Sen , Kinjal Banerjee , T. K. Jha

The shear viscosity for a heated granular binary mixture of smooth hard spheres at low-density is analyzed. The mixture is heated by the action of an external driving force (Gaussian thermostat) which exactly compensate for cooling effects…

Statistical Mechanics · Physics 2009-11-07 J. M. Montanero , V. Garzo

We determine the shear viscosity of the ultracold Fermi gas at unitarity in the normal phase using hydrodynamic expansion data. The analysis is based on a generalized fluid dynamic framework which ensures a smooth transition between the…

Quantum Gases · Physics 2017-08-16 Marcus Bluhm , Jiaxun Hou , Thomas Schaefer

Using the anti-de Sitter/conformal field theory correspondence, we relate the shear viscosity \eta of the finite-temperature N=4 supersymmetric Yang-Mills theory in the large N, strong-coupling regime with the absorption cross section of…

High Energy Physics - Theory · Physics 2010-02-18 G. Policastro , D. T. Son , A. O. Starinets

We show that equations governing pulsations of superfluid neutron stars can be splitted into two sets of weakly coupled equations, one describing the superfluid modes and another one -- the normal modes. The coupling parameter s is small,…

Solar and Stellar Astrophysics · Physics 2012-01-19 M. E. Gusakov , E. M. Kantor

The possible $^{1}S_{0}$ protonic superfluidity is investigated in neutron star matter, and the corresponding energy gap as a function of baryonic density is calculated on the basis of BCS gap equation. We have discussed particularly the…

High Energy Astrophysical Phenomena · Physics 2017-02-12 Xu Yan , Zhang Xiao-Jun , Fan Cun-Bo , Tmurbagan Bao , Huang Xiu-Lin , Liu Cheng-Zhi

We compute the bulk, $\zeta$, and shear, $\eta$, viscosity over entropy density, $s$, for the QCD matter formed in small collision systems at LHC. We consider a scenario of the String Percolation Model by proposing a global form of the…

High Energy Physics - Phenomenology · Physics 2023-12-06 J. R. Alvarado García , I. Bautista , A. Fernández Téllez , P. Fierro

The neutron star crustal EoS and transition point properties are computed within a unified meta-modeling approach. A Bayesian approach is employed including two types of filters: bulk nuclear properties are controlled from low density…

Nuclear Theory · Physics 2019-11-20 Thomas Carreau , Francesca Gulminelli , Jérôme Margueron

The shear viscosity of a gluon gas is calculated using the Green-Kubo relation. Time correlations of the energy-momentum tensor in thermal equilibrium are extracted from microscopic simulations using a parton cascade solving various…

High Energy Physics - Phenomenology · Physics 2013-05-29 C. Wesp , A. El , F. Reining , Z. Xu , I. Bouras , C. Greiner

Using Grad's method, we calculate the entropy production and derive a formula for the second-order shear viscosity coefficient in a one-dimensionally expanding particle system, which can also be considered out of chemical equilibrium. For a…

High Energy Physics - Phenomenology · Physics 2010-04-21 Andrej El , Zhe Xu , Carsten Greiner , Azwinndini Muronga

We analyse the implications of superfluid turbulence for neutron star physics. We begin by extending our previous results for the mutual friction force for a straight vortex array to account for the self-induced flow which arises when the…

Astrophysics · Physics 2012-11-16 N. Andersson , T. Sidery , G. L. Comer

The shear viscosity of an interacting pion gas is studied using the Kubo formalism as a microscopic description of thermal systems close to global equilibrium. We implement the skeleton expansion in order to approximate the retarded…

High Energy Physics - Phenomenology · Physics 2012-09-05 Robert Lang , Norbert Kaiser , Wolfram Weise

The momentum dependent lineshape of the out-of-phase oxygen vibration as measured in recent neutron scattering measurements is investigated. Starting from a microscopic coupling of the phonon vibration to a local crystal field, the phonon…

Superconductivity · Physics 2009-10-31 T. P. Devereaux , A. Virosztek , A. Zawadowski

Within the framework of relativistic fluctuating hydrodynamics we compute the contribution of thermal fluctuations to the effective infrared shear viscosity of a conformal fluid, focusing on quadratic (in fluctuations), second order (in…

High Energy Physics - Phenomenology · Physics 2015-05-30 J. Peralta-Ramos , E. Calzetta

We derive an analytic expression for the shear viscosity of an ultra-relativistic gas in presence of both elastic $2\to 2$ and inelastic $2\leftrightarrow 3$ processes with isotropic differential cross sections. The derivation is based on…

High Energy Physics - Theory · Physics 2014-04-28 Andrej El , Francesco Lauciello , Christian Wesp , Ioannis Bouras , Zhe Xu , Carsten Greiner

We present calculations of the hydrodynamics of the inner crust of neutron stars, where a superfluid neutron liquid coexists with a lattice of neutron-rich nuclei. The long-wavelength collective oscillations are combinations of phonons in…

Nuclear Theory · Physics 2015-06-15 D. Kobyakov , C. J. Pethick

We explore the viscosities of a photon gas by means of the Euler-Heisenberg effective theory and quantum electrodynamics at zero electron chemical potential. We find parametric estimates that show a very large shear viscosity and an…

High Energy Physics - Phenomenology · Physics 2013-09-19 Antonio Dobado , Felipe J. Llanes-Estrada , Juan M. Torres-Rincon

We show that the shear modes in the neutron star crust are quite sensitive to the existence of nonuniform nuclear structures, so-called "pasta". Due to the existence of pasta phase, the frequencies of shear modes are reduced, where the…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Hajime Sotani