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Related papers: How viscous is a superfluid neutron star core?

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In this brief summary I describe our recent work on superfluid neutron star dynamics. I review results on shear viscosity, hyperon bulk viscosity, vortex mediated mutual friction and the modelling of multifluid systems in general. For each…

Astrophysics · Physics 2008-11-26 N. Andersson

We study the shear and bulk viscosity coefficients as well as the thermal conductivity as arising from the collisions among phonons in superfluid neutron stars. We use effective field theory techniques to extract the allowed phonon…

Solar and Stellar Astrophysics · Physics 2014-12-01 Laura Tolos , Cristina Manuel , Sreemoyee Sarkar , Jaume Tarrus

We study the effects of an elastic crust on the oscillation spectrum of superfluid neutron stars. Within the two fluid formalism, we consider Newtonian stellar models that include the relevant constituents of a mature neutron stars. The…

Solar and Stellar Astrophysics · Physics 2015-05-28 A. Passamonti , N. Andersson

The bulk viscosity of the neutron star matter due to the direct Urca processes involving nucleons, electrons and muons is studied taking into account possible superfluidity of nucleons in the neutron star cores. The cases of singlet-state…

Astrophysics · Physics 2009-05-13 P. Haensel , K. P. Levenfish , D. G. Yakovlev

We study the effect of superfluidity on the tidal response of a neutron star in a general relativistic framework. In this work, we take a dual-layer approach where the superfluid matter is confined in the core of the star. Then, the…

General Relativity and Quantum Cosmology · Physics 2020-09-16 Sayak Datta , Prasanta Char

We study the bulk viscosity in neutron star cores due to modified Urca processes involving nucleons, electrons and muons and analize its reduction by singlet-state or triplet-state superfluidity of nucleons. In combination with the results…

Astrophysics · Physics 2009-11-06 P. Haensel , K. P. Levenfish , D. G. Yakovlev

This review focuses on applications of the ideas of superfluidity and superconductivity in neutron stars in a broader context, ranging from the microphysics of pairing in nucleonic superfluids to macroscopic manifestations of superfluidity…

High Energy Astrophysical Phenomena · Physics 2019-03-06 Brynmor Haskell , Armen Sedrakian

Bulk viscosity of neutron star cores containing hyperons is studied taking into account non-equilibrium weak process $n+n \rightleftharpoons p+\Sigma^-$. Rapid growth of the bulk viscosity within the neutron star core associated with…

Astrophysics · Physics 2010-02-05 P. Haensel , K. P. Levenfish , D. G. Yakovlev

We show that electrons can couple to the neutron excitations in neutron stars and find that this can limit their contribution to the transport properties of dense matter, especially the shear viscosity. The coupling between electrons and…

Nuclear Theory · Physics 2015-03-05 Bridget Bertoni , Sanjay Reddy , Ermal Rrapaj

We calculate the shear viscosity $\eta = \eta_{e\mu}+\eta_{n}$ in a neutron star core composed of nucleons, electrons and muons ($\eta_{e\mu}$ being the electron-muon viscosity, mediated by collisions of electrons and muons with charged…

Astrophysics · Physics 2009-02-20 P. S. Shternin , D. G. Yakovlev

We review the effective field theory associated with the superfluid phonons that we use for the study of transport properties in the core of superfluid neutrons stars in their low temperature regime. We then discuss the shear and bulk…

Nuclear Theory · Physics 2021-03-08 Cristina Manuel , Laura Tolos

As mature neutron stars are cold (on the relevant temperature scale), one has to carefully consider the state of matter in their interior. The outer kilometer or so is expected to freeze to form an elastic crust of increasingly neutron-rich…

High Energy Astrophysical Phenomena · Physics 2021-03-19 N. Andersson

In order to establish whether the unstable r-modes in a rotating neutron star provide a detectable source of gravitational waves, we need to understand the details of the many dissipative processes that tend to counteract the instability.…

Solar and Stellar Astrophysics · Physics 2015-05-18 Brynmor Haskell , Nils Andersson

The phonon contribution to the shear viscosity $\eta$ in superfluid neutron stars is calculated by assuming neutron pairing in a $^1S_0$ channel. The shear viscosity is obtained by means of variational methods for the solution of the…

High Energy Astrophysical Phenomena · Physics 2012-06-19 Laura Tolos , Cristina Manuel

We investigate the combined effect of neutron and proton superfluidities on the cooling of neutron stars whose cores consist of nucleons and electrons. We consider singlet-state pairing of protons and triplet-state pairing of neutrons in…

Astrophysics · Physics 2009-11-10 M. E. Gusakov , A. D. Kaminker , D. G. Yakovlev , O. Y. Gnedin

We survey the current status of understanding of pairing and superfluidity of neutrons and protons in neutron stars from a theoretical perspective, with emphasis on basic physical properties. During the past two decades, the blossoming of…

Nuclear Theory · Physics 2015-04-15 A. Gezerlis , C. J. Pethick , A. Schwenk

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

We discuss the nature of the various modes of pulsation of superfluid neutron stars using comparatively simple Newtonian models. The matter in these stars is described in terms of a two-fluid model, where one fluid is the neutron…

Astrophysics · Physics 2011-07-18 N. Andersson , G. L. Comer

Mature neutron stars are cold enough to contain a number of superfluid and superconducting components. These systems are distinguished by the presence of additional dynamical degrees of freedom associated with superfluidity. In order to…

Solar and Stellar Astrophysics · Physics 2015-05-18 K. Glampedakis , N. Andersson , L. Samuelsson

The shear viscosity of the crust might have a damping effect on the amplitude of r-modes of rotating neutron stars. This damping has implications for the emission of gravitational waves. We calculate the contribution to the shear viscosity…

Astrophysics · Physics 2008-11-26 O. L. Caballero , S. Postnikov , C. J. Horowitz , M. Prakash
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