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Related papers: Bulk viscosity of superfluid hyperon stars

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The viscosity of liquids under nanoconfinement remains controversial. Reports range from spontaneous solidification to no change in the viscosity at all. Here, we present thorough measurements with a small-amplitude linear atomic force…

Soft Condensed Matter · Physics 2012-10-15 Shah H. Khan , Peter M. Hoffmann

We develop a nonlinear generalisation of the causal linear thermodynamics of bulk viscosity, incorporating positivity of the entropy production rate and the effective specific entropy. The theory is applied to viscous fluid inflation (which…

Astrophysics · Physics 2009-10-28 Roy Maartens , Vicenc Mendez

The role of the isoscalar hyperon Lambda in probing the density dependence of the nuclear symmetry energy is studied in multi-Lambda hypernuclei, hyperon-rich matter and neutron stars in relativistic models. Relationships between the…

Nuclear Theory · Physics 2008-11-26 W. Z. Jiang

The bulk viscosity in spin-one color-superconducting strange quark matter is calculated by taking into account the interplay between the nonleptonic and semi-leptonic week processes. In agreement with previous studies, it is found that the…

High Energy Physics - Phenomenology · Physics 2014-11-21 Xinyang Wang , Igor A. Shovkovy

We investigate the weak-interaction-driven bulk-viscous transport properties of $npe$ matter in the neutrino transparent regime. Previous works assumed that the induced bulk viscosity correction to pressure, near beta equilibrium, is linear…

Nuclear Theory · Physics 2023-12-20 Yumu Yang , Mauricio Hippert , Enrico Speranza , Jorge Noronha

In this paper we present a computation of the rates of strangeness-changing processes and the resultant bulk viscosity in matter at the densities and temperatures typical of neutron star mergers. To deal with the high temperature in this…

Nuclear Theory · Physics 2021-05-05 Mark G. Alford , Alexander Haber

We present a simple (microscopic) model in which bulk viscosity plays a role in explaining the present acceleration of the universe. The effect of bulk viscosity on the Friedmann equations is to turn the pressure into an "effective"…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-23 Jean-Sebastien Gagnon , Julien Lesgourgues

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

We show that first approximations to the bulk viscosity $\eta_v$ are expressible in terms of factors that depend on the sound speed $v_s$, the enthalpy, and the interaction (elastic and inelastic) cross section. The explicit dependence of…

Nuclear Theory · Physics 2009-11-18 A. Wiranata , M. Prakash

The quasielastic weak production of $\Lambda$ and $\Sigma$ hyperons from nucleons and nuclei induced by antineutrinos is studied in the energy region of some ongoing neutrino oscillation experiments in the intermediate energy region. The…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. K. Singh , M. J. Vicente Vacas

Recent breakthrough experiments on dipolar condensates have reported the creation of supersolids, including two-dimensional arrays of quantum droplets. Droplet arrays are, however, not the only possible non-trivial density arrangement…

Quantum Gases · Physics 2022-12-14 Albert Gallemí , Luis Santos

The dynamics of quantised vorticity in neutron star interiors is at the heart of most pulsar glitch models. However, the large number of vortices (up to $\approx 10^{13}$) involved in a glitch and the huge disparity in scales between the…

High Energy Astrophysical Phenomena · Physics 2018-06-27 Vadym Khomenko , Brynmor Haskell

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

By employing a recently constructed hyperon-nucleon potential the equation of state of \beta-equilibrated and charge neutral nucleonic matter is calculated. The hyperon-nucleon potential is a low-momentum potential which is obtained within…

Nuclear Theory · Physics 2014-11-18 Haris Djapo , Bernd-Jochen Schaefer , Jochen Wambach

We solve second order relativistic hydrodynamics equations for a boost-invariant 1+1-dimensional expanding fluid with an equation of state taken from lattice calculations of the thermodynamics of strongly coupled quark-gluon plasma. We…

High Energy Physics - Phenomenology · Physics 2010-03-19 Krishna Rajagopal , Nilesh Tripuraneni

We study non-radial oscillations of neutron stars with superfluid baryons, in a general relativistic framework, including finite temperature effects. Using a perturbative approach, we derive the equations describing stellar oscillations,…

General Relativity and Quantum Cosmology · Physics 2014-07-09 L. Gualtieri , E. M. Kantor , M. E. Gusakov , A. I. Chugunov

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

Based on the Kaplan-Nelson Lagrangian, we investigate kaon condensation in dense neutron star matter allowing for the explicit presence of hyperons. Using various models we find that the condensate threshold is sensitive to the behavior of…

Nuclear Theory · Physics 2016-09-08 Paul J. Ellis , Roland Knorren , Madappa Prakash

We perform a detailed analysis of radial oscillations to discuss dynamical stability in two-fluid neutron stars composed of ordinary nuclear matter and a gravitationally coupled dark matter component. Using a fully relativistic two-fluid…

High Energy Astrophysical Phenomena · Physics 2025-09-05 Ankit Kumar , Hajime Sotani

Heavy elements are synthesized by the r-process in neutron star mergers and potentially in rare supernovae linked to strong magnetic fields. Expensive hydrodynamic simulations of these extreme environments are usually post-processed to…

High Energy Astrophysical Phenomena · Physics 2025-06-03 Jan Kuske , Almudena Arcones , Moritz Reichert
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