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Related papers: Bulk Viscosity in Neutron Stars from Hyperons

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We describe distinctive stellar features indicating the presence of hyperons in neutron stars as compared to purely nucleonic systems. A strongly negative curvature of the mass-radius relation $R(M)$ is characteristic of hyperons, which can…

We estimate bulk and shear viscosity at finite temperature and baryon densities of hadronic matter within hadron resonance gas model. For bulk viscosity we use low energy theorems of QCD for the energy momentum tensor correlators. For shear…

High Energy Physics - Phenomenology · Physics 2015-05-20 Guru Prakash Kadam , Hiranmaya Mishra

During the inspiral of a binary neutron star, viscous processes in the neutron star matter can damp out the tidal energy induced by its companion and convert it to thermal energy. This tidal dissipation/heating process introduces a net…

General Relativity and Quantum Cosmology · Physics 2025-10-15 Suprovo Ghosh , Samanwaya Mukherjee , Sukanta Bose , Debarati Chatterjee

We analyze the influence of hyperons in binary neutron star mergers considering several different equations of state that include hyperons. By running a large set of simulations, we study the impact of the thermally produced hyperons on the…

High Energy Astrophysical Phenomena · Physics 2025-07-25 Laura Tolos , Hristijan Kochankovski , Angels Ramos , Georgios Lioutas , Sebastian Blacker , Andreas Bauswein

The equation of state (EOS) of dense matter in neutron stars (NSs) remains uncertain, particularly at supra-nuclear densities where complex nuclear interactions and the potential presence of exotic matter, like hyperons, come into play. The…

Nuclear Theory · Physics 2026-01-13 N. K. Patra , Tuhin Malik , Kai Zhou , Constança Providência

On the basis of the percolation picture from the hadronic phase with hyperons to the quark phase with strangeness, we construct a new equation of state (EOS) with the pressure interpolated as a function of the baryon density. The maximum…

Nuclear Theory · Physics 2016-06-21 Kota Masuda , Tetsuo Hatsuda , Tatsuyuki Takatsuka

We consider the so called hyperon puzzle of neutron star (NS). We employ Skyrme force models for the description of in-medium nucleon-nucleon, nucleon-Lambda hyperon ($N\Lambda$), and Lambda-Lambda ($\Lambda\Lambda$) interactions. A…

Nuclear Theory · Physics 2016-01-27 Yeunhwan Lim , Chang Ho Hyun , Kyujin Kwak , Chang-Hwan Lee

We develop new hyperon equation of state (EoS) tables for core-collapse supernova simulations and neutron stars. These EoS tables are based on a density-dependent relativistic hadron field theory where baryon-baryon interaction is mediated…

High Energy Astrophysical Phenomena · Physics 2015-03-03 Sarmistha Banik , Matthias Hempel , Debades Bandyopadhyay

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

Understanding the equation of state of dense nuclear matter is a fundamental challenge for nuclear physics. It is especially timely and interesting challenge as we have reached a period where neutron stars, which contain the most dense…

Nuclear Theory · Physics 2022-01-28 Theo F. Motta , Anthony W. Thomas

The so called "hyperon puzzle", i.e. the difficulty to reconcile the measured masses of neutron stars (NSs) with the presence of hyperons in their interiors, is one of the hot topics in astrophysics which is stimulating copious experimental…

Nuclear Theory · Physics 2017-08-02 Ignazio Bombaci

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

A novel equation of state used for analysis of the heavy ion collision experimental data is generalized to also describe the matter inside neutron stars. This approach differs from others by including an induced surface tension caused by…

High Energy Astrophysical Phenomena · Physics 2019-02-20 V. Sagun , I. Lopes , A. Ivanytskyi

The history and recent progresses in the study of bulk viscosity in nuclear and quark matter are reviewed. The constraints from baryon number conservation and electric neutrality in quark matter on particle densities and fluid velocity…

Astrophysics · Physics 2008-11-26 Hui Dong , Nan Su , Qun Wang

The measurement of $1.97 \pm 0.04 M_{solar}$ for PSR J1614-2230 and $2.01 \pm 0.04M_{solar}$ for PSR J0348+0432 puts a strong constraint on the neutron star equation of state and its exotic composition at higher densities. In this paper, we…

High Energy Astrophysical Phenomena · Physics 2014-07-11 Prasanta Char , Sarmistha Banik

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

The parity doublet model, containing the SU(2) multiplets including the baryons identified as the chiral partners of the nucleons is applied to neutron stars. The maximum mass for the star is calculated for different stages of the cooling…

Astrophysics · Physics 2008-01-17 V. Dexheimer , S. Schramm , H. Stoecker

The study focuses on exploring the changes in the hyperon-baryon interaction at various nuclear densities. This approach starts by building a vacuum hyperon-nucleon interaction model based on Boson -Exchange maintaining SU(3) flavor…

Nuclear Theory · Physics 2022-11-30 Madhumita Dhar , Horst Lenske

In this work, we have calculated the transport coefficients: shear viscosity and thermal conductivity inside the neutron star core. Our calculation is based on the relativistic kinetic theory approach using a modified BUU equation for…

Nuclear Theory · Physics 2026-03-20 Utsab Gangopadhyaya , Suman Pal , Gargi Chaudhuri

Since 2013 the mass of pulsar PSR J0348+0432 ($M = 2.01\,M_{\odot}$) has provided a tight constraint on neutron star equation of state. However, a number of different analyses of the recently detected BNS merger (GW170817) point to a…

Nuclear Theory · Physics 2019-04-10 William M. Spinella , Fridolin Weber