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Related papers: Shear viscosity in superfluid neutron stars

200 papers

We calculate the electron shear viscosity (determined by Coulomb electron collisions) for a dense matter in a wide range of parameters typical for white dwarf cores and neutron star crusts. In the density range from ~10^3 g cm^-3 to…

Astrophysics · Physics 2009-11-13 A. I. Chugunov , D. G. Yakovlev

We compute the shear viscosity, $\eta$, at general temperatures $T$, in a BCS-BEC crossover scheme which is demonstrably consistent with conservation laws. The study of $\eta$ is important because it constrains microscopic theories by…

Quantum Gases · Physics 2011-08-04 H. Guo , D. Wulin , C. C. Chien , K. Levin

We investigate the effects of baryon chemical potential \mu on the shear viscosity coefficient \eta and the viscosity to entropy density ratio \eta/s of a pion-nucleon gas mixture. We find that \eta is an increasing function of T and \mu,…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. Itakura , O. Morimatsu , H. Otomo

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…

Nuclear Theory · Physics 2014-11-20 Subrata Pal

We investigate the shear viscosity of neutron star matter in the presence of an antikaon condensate. The electron and muon number densities are reduced due to the appearance of a $K^-$ condensate in neutron star matter, whereas the proton…

Solar and Stellar Astrophysics · Physics 2010-04-23 Rana Nandi , Sarmistha Banik , Debades Bandyopadhyay

The hydrodynamics, describing dynamical effects in superfluid neutron stars, essentially differs from the standard one-fluid hydrodynamics. In particular, we have four bulk viscosity coefficients in the theory instead of one. In this paper…

Astrophysics · Physics 2008-12-18 M. E. Gusakov

Within a Boltzmann transport model, we demonstrate correlation between stopping observables and shear viscosity in central nuclear collisions at intermediate energies (on the order of 10 to 1000 MeV/nucleon). The correlation allows us to…

Nuclear Theory · Physics 2019-03-27 Brent Barker , Pawel Danielewicz

The specific shear viscosity $\bar\eta$ of a classically rotating system of nucleons that interact via a monopole pairing interaction is calculated including the effects of thermal fluctuations and coupling to pair vibrations within the…

Nuclear Theory · Physics 2015-06-05 N. Quang Hung , N. Dinh Dang

The shear viscosity tensor of the superfluid Fermi gas in p-wave state with weak interaction is calculated at low temperatures, by using the Boltzmann equation approach. We consider the transition probabilities for the binary, decay and…

Quantum Gases · Physics 2016-03-09 Soudabe Nasirimoghadam , Roohollah Aliabadi , Mohamad Ali Shahzamanian

We discuss in detail the shear viscosity coefficient eta and the viscosity to entropy density ratio eta/s of a hadronic gas comprised of pions and nucleons. In particular, we study the effects of baryon chemical potential on eta and eta/s.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Kazunori Itakura , Osamu Morimatsu , Hiroshi Otomo

The electron shear viscosity due to Coulomb scattering of degenerate electrons by atomic nuclei throughout a magnetized neutron star crust is calculated. The theory is based on the shear viscosity coefficient calculated neglecting magnetic…

Solar and Stellar Astrophysics · Physics 2015-12-22 D. D. Ofengeim , D. G. Yakovlev

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…

High Energy Physics - Theory · Physics 2009-02-09 Rong-Gen Cai , Ya-Wen Sun

I derive an exact integral expression for the ratio of shear viscosity over entropy density $\frac{\eta}{s}$ for the massless (critical) O(N) model at large N with quartic interactions. The calculation is set up and performed entirely from…

High Energy Physics - Theory · Physics 2021-12-23 Paul Romatschke

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…

High Energy Physics - Phenomenology · Physics 2009-01-01 Jiunn-Wei Chen , Mei Huang , Yen-Han Li , Eiji Nakano , Di-Lun Yang

We compute the shear viscosity of the unitary Fermi gas above the superfluid transition temperature, using a diagrammatic technique that starts from the exact Kubo formula. The formalism obeys a Ward identity associated with scale…

Quantum Gases · Physics 2011-02-01 Tilman Enss , Rudolf Haussmann , Wilhelm Zwerger

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 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 calculation of transport properties of Fermi liquids, based on the formalism developed by Abrikosov and Khalatnikov, requires the knowledge of the probability of collisions between quasiparticles in the vicinity of the Fermi surface. We…

Nuclear Theory · Physics 2008-11-26 Omar Benhar , Marco Valli

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

The ratio of shear viscosity to entropy density, $\eta/s$, is computed in various holographic geometries that break translation invariance (but are isotropic). The shear viscosity does not have a hydrodynamic interpretation in such…

High Energy Physics - Theory · Physics 2016-04-20 Sean A. Hartnoll , David M. Ramirez , Jorge E. Santos