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Related papers: Bulk Viscosity in Neutron Stars from Hyperons

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Nucleon spin fluctuations in a dense medium reduce the ``naive'' values of weak interaction rates (neutrino opacities, neutrino emissivities). We extend previous studies of this effect to the degenerate case which is appropriate for neutron…

Astrophysics · Physics 2014-10-13 Georg Raffelt , Thomas Strobel

In this work, we estimate how much bulk viscosity driven by Urca processes is likely to affect the gravitational wave signal of a neutron star coalescence. In the late inspiral, we show that bulk viscosity affects the binding energy at…

The production of light nuclei and hypernuclei together with heavy baryons, both hyperons and $\Delta$-baryons, in low density matter as found in stellar environments such as supernova or binary mergers is studied within relativistic…

Nuclear Theory · Physics 2022-06-29 Tiago Custódio , Helena Pais , Constança Providência

We consider the effect of hard core repulsion in the baryon-baryon interaction at short distance to the properties of a neutron star. We obtain that, even with hyperons in the interior of a neutron star, the neutron star mass can be as…

Nuclear Theory · Physics 2008-11-26 Chang Ho Hyun

After an introduction to the QCD phase diagram, the nuclear equations of state, and neutron star mergers, I discuss three projects related to transport and nuclear matter in neutron star mergers. The first is the nature of beta equilibrium…

Nuclear Theory · Physics 2021-11-24 Steven P. Harris

We investigate a first-order phase transition from hadronic matter to antikaon condensed matter during the cooling stage of protoneutron stars. The phase transition proceeds through the thermal nucleation of antikaon condensed matter. In…

High Energy Astrophysical Phenomena · Physics 2011-01-20 Sarmistha Banik , Debades Bandyopadhyay

We consider transport properties of the hypernuclear matter in neutron star cores. In particular, we calculate the thermal conductivity, the shear viscosity, and the momentum transfer rates for np$\Sigma^{-}\Lambda e\mu$ composition of…

High Energy Astrophysical Phenomena · Physics 2021-06-24 Peter Shternin , Isaac Vidaña

We study bulk viscosity arising from weak current Urca processes in dense baryonic matter at and beyond nuclear saturation density. We consider the temperature regime where neutrinos are trapped and therefore have nonzero chemical…

High Energy Astrophysical Phenomena · Physics 2019-11-27 Mark Alford , Arus Harutyunyan , Armen Sedrakian

Using the Dirac-Brueckner-Hartree-Fock approach, the properties of neutron-star matter including hyperons are investigated. In the calculation, we consider both time and space components of the vector self-energies of baryons as well as the…

Nuclear Theory · Physics 2015-01-23 Tetsuya Katayama , Koichi Saito

We look at viscosity production in a universe consisting purely of leptons and photons. This is quite close to what the Universe actually look like when the temperature was between $10^{10}$ K and $10^{12}$ K ($1$ -- $100$ MeV). By taking…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-18 Lars Husdal

We investigate the effects of the light vector U-boson that couples weakly to nucleons in relativistic mean-field models on the equation of state and subsequently the consequence in neutron stars. It is analyzed that the U-boson can lead to…

Nuclear Theory · Physics 2015-03-19 Dong-Rui Zhang , Ping-Liang Yin , Wei Wang , Qi-Chao Wang , Wei-Zhou Jiang

We investigate the properties of an antikaon in medium, regarding itas a MIT bag. We first construct the MIT bag model for a kaon with$\sigma^*$ and $\phi$ in order to describe the interaction of$s$-quarks in hyperonic matter in the…

Nuclear Theory · Physics 2010-04-30 C. Y. Ryu , C. H. Hyun , S. W. Hong

Out-of-equilibrium reactions between different particle species are the main processes contributing to bulk viscosity in neutron stars. In this work, we numerically compare three different approaches to the modeling of bulk viscosity: the…

General Relativity and Quantum Cosmology · Physics 2023-05-23 Giovanni Camelio , Lorenzo Gavassino , Marco Antonelli , Sebastiano Bernuzzi , Brynmor Haskell

The constituents of cold dense matter are still far from being understood. However, neutron star observations such as the recently observed pulsar PSR J1614-2230 with a mass of 1.97+/-0.04 M_solar help to considerably constrain the hadronic…

High Energy Astrophysical Phenomena · Physics 2012-04-30 Simon Weissenborn , Debarati Chatterjee , Juergen Schaffner-Bielich

The early post-merger phase of a binary neutron-star coalescence is shaped by characteristic rotational velocities as well as violent density oscillations and offers the possibility to constrain the properties of neutron star matter by…

General Relativity and Quantum Cosmology · Physics 2025-03-10 Michail Chabanov , Luciano Rezzolla

Hyperons are essential constituents in the neutron star interior. The poorly-known hyperonic interaction is a source of uncertainty for studying laboratory hypernuclei and neutron star observations. In this work, we perform Bayesian…

High Energy Astrophysical Phenomena · Physics 2023-01-13 Xiangdong Sun , Zhiqiang Miao , Baoyuan Sun , Ang Li

We discuss $\beta$-equilibrated and charge neutral matter involving hyperons and $\bar K$ condensates within relativistic models. It is observed that populations of baryons are strongly affected by the presence of antikaon condensates.…

Nuclear Theory · Physics 2009-09-29 Debades Bandyopadhyay

In this contribution we review the dynamics of hyperons with nucleons and nuclear matter, paying a special attention to hypernuclei. We also discuss the presence of hyperons in the inner core of neutron stars and the consequences for the…

Nuclear Theory · Physics 2022-02-16 Laura Tolos

In the framework of the Brueckner-Bethe-Goldstone theory, we determine a fully microscopic equation of state for asymmetric and $\beta$-stable nuclear matter containing $\sim$ and $\la$ hyperons. We use the Paris and the new Argonne…

Nuclear Theory · Physics 2009-07-09 M. Baldo , G. F. Burgio , H. -J. Schulze

The bulk viscosity in quark matter is sufficiently high to reduce the effective pressure below the corresponding vapor pressure during density perturbations in neutron stars and strange stars. This leads to mechanical instability where the…

Solar and Stellar Astrophysics · Physics 2009-09-30 Jes Madsen
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