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Related papers: Shear viscosity in neutron star cores

200 papers

The shear viscosity $\eta$ for a dilute classical gas of hard-sphere particles is calculated by solving the Boltzmann kinetic equation in terms of the weakly absorbed plane waves. For the rare-collision regime, the viscosity $\eta$ as a…

Statistical Mechanics · Physics 2018-01-29 A. G. Magner , M. I. Gorenstein , U. V. Grygoriev

At finite temperature (T) there is a link with general relativity and hydrodynamics that leads to a lower bound for the ratio of shear viscosity and entropy density (\eta/s). We find that the bound is saturated in the simple model for quark…

High Energy Physics - Phenomenology · Physics 2007-06-13 Sibasish Laha , Taparati Gangopadhyay , Manjari Bagchi , Mira Dey , Jishnu Dey , Monika Sinha , Subharthi Ray

We investigate the rates of production and thermalization of $\nu_\mu$ and $\nu_\tau$ neutrinos at temperatures and densities relevant to core-collapse supernovae and protoneutron stars. Included are contributions from electron scattering,…

Astrophysics · Physics 2008-11-26 Todd A. Thompson , Adam Burrows , J. E. Horvath

Neutron star tidal deformability extracted from gravitational wave data provides a novel probe to the interior neutron star structures and the associated nuclear equation of state (EOS). Instead of the popular composition of nucleons and…

Nuclear Theory · Physics 2021-09-27 W. Z. Shangguan , Z. Q. Huang , S. N. Wei , W. Z. Jiang

We study neutrino energy emission rates (emissivities) due to electron bremsstrahlung produced by $ee$ and $ep$ collisions in the superfluid neutron star cores. The neutrino emission due to $ee$ collisions is shown to be the dominant…

Astrophysics · Physics 2011-03-17 A. D. Kaminker , P. Haensel

Shear viscosity (eta) of QCD in the hadronic phase is computed by the coupled Boltzmann equations of pions and nucleons in low temperatures and low baryon number densities. The eta to entropy density ratio eta/s maps out the nuclear…

High Energy Physics - Phenomenology · Physics 2008-11-26 Jiunn-Wei Chen , Yen-Han Li , Yen-Fu Liu , Eiji Nakano

Properties and structure of neutron stars are determined by the equation of state (EOS) of neutron-rich stellar matter. While the collective flow and particle production in relativistic heavy-ion collisions have constrained tightly the EOS…

Astrophysics · Physics 2008-04-22 Aaron Worley , Plamen G. Krastev , Bao-An Li

The specific viscosity of neutron-rich nuclear matter is studied from the relaxation time approach using an isospin- and momentum-dependent interaction and the nucleon-nucleon cross sections taken as those from the experimental data…

Nuclear Theory · Physics 2011-12-06 Jun Xu

An ambitious goal of the astrophysical community is not only to constrain the equation of state (EOS) of neutron star (NS) matter by confronting it with astrophysics observations, but ultimately also to infer the NS composition.…

Nuclear Theory · Physics 2022-11-09 Tuhin Malik , B. K. Agrawal , Constança Providência

The temperature and density dependence of the relaxation times, thermal conductivity, shear viscosity and bulk viscosity for a hot and dense gas consisting of pions, kaons and nucleons have been evaluated in the kinetic theory approach. The…

Employing a simplified version of the Israel-Stewart formalism for general-relativistic shear-viscous hydrodynamics, we perform axisymmetric general-relativistic simulations for a rotating neutron star surrounded by a massive torus, which…

High Energy Astrophysical Phenomena · Physics 2017-04-26 Masaru Shibata , Kenta Kiuchi , Yu-ichiro Sekiguchi

We study non-linear effects of radiative viscosity of $npe$ matter in neutron stars for both direct Urca process and modified Urca process, and find that non-linear effects will decrease the ratio of radiative viscosity to bulk viscosity…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Shu-Hua Yang , Xiao-Ping Zheng , Chun-Mei Pi

We extend our modeling of cooling of superfluid neutron stars by including the production of muons in the core, in addition to neutrons, protons, and electrons. The results are confronted with observations of middle-aged isolated NSs. Muons…

Astrophysics · Physics 2007-05-23 M. Bejger , D. G. Yakovlev , O. Y. Gnedin

We calculated bulk viscosity due to non-equilibrium weak processes in superfluid nucleon-hyperon matter of neutron stars. For that, the dissipative relativistic hydrodynamics, formulated in paper [1] for superfluid mixtures, was extended to…

Astrophysics · Physics 2008-11-26 M. E. Gusakov , E. M. Kantor

The crustal fraction of moment of inertia in neutron stars is calculated using $\beta$-equilibrated nuclear matter obtained from density dependent M3Y effective interaction. The transition density, pressure and proton fraction at the inner…

Nuclear Theory · Physics 2017-02-21 Debasis Atta , Somnath Mukhopadhyay , D. N. Basu

The consistency between electron-scattering and proton-scattering is examined through the fourth moment of the charge distribution.

Nuclear Theory · Physics 2024-07-17 Toshio Suzuki , Rika Danjo , Toshimi Suda

We adopt two- and three-body nuclear forces derived at the next-to-next-to-leading-order (N2LO) in the framework of effective chiral perturbation theory (ChPT) to calculate the equation of state (EOS) of $\beta$-stable neutron star matter…

High Energy Astrophysical Phenomena · Physics 2018-06-27 Domenico Logoteta , Ignazio Bombaci

In the real-time thermal field theory, the standard expression of shear viscosity for the nucleonic constituents is derived from the two point function of nucleonic viscous stress tensors at finite temperature and density. The finite…

Nuclear Theory · Physics 2015-03-25 Sabyasachi Ghosh

We study the effects of isovector-scalar meson $\delta$ on the equation of state (EOS) of neutron star matter in strong magnetic fields. The EOS of neutron-star matter and nucleon effective masses are calculated in the framework of…

Nuclear Theory · Physics 2009-11-11 F. X. Wei , G. J. Mao , C. M. Ko , L. S. Kisslinger , H. Stoecker , W. Greiner

In recent years, there has been a significant effort to extract the temperature-dependent shear ($\eta/s$) and bulk ($\zeta/s$) viscosity over entropy ratios of the quark-gluon plasma from a global comparison of heavy-ion data with results…

Nuclear Theory · Physics 2023-02-28 Fernando G. Gardim , Jean-Yves Ollitrault