Related papers: Bulk Viscosity in Neutron Stars from Hyperons
The variation of kaon mass in dense, charge-neutral baryonic matter at beta-equilibrium has been investigated. The baryon interaction has been included by means of nonlinear Walecka model, with and without hyperons and the interaction of…
We study the properties of neutron star using the chiral quark-meson coupling model, in which the quark-quark hyperfine interaction due to the exchanges of gluon and pion based on chiral symmetry is considered. We also examine the effects…
Recent measurement of mass of PSR J1614-2230 rules out most of existing models of equation of state (EOS) of dense matter with high-density softening due to hyperonization or a phase transition to quark matter or a boson condensate. We look…
We construct new equations of state for baryons at sub-nuclear densities for the use in core-collapse simulations of massive stars. The abundance of various nuclei is obtained together with thermodynamic quantities. A model free energy is…
Chiral Lagrangian and quark-meson coupling models of hyperon matter are used to estimate the maximum mass of neutron stars. Our relativistic calculations include, for the first time, both Hartree and Fock contributions in a consistent…
In this work we present results for pairing gaps in $\beta$--stable neutron star matter with electrons and muons using a relativistic Dirac--Brueckner--Hartree--Fock approach, starting with modern meson--exchange models for the…
We study a cosmological model composed of a dark energy fluid interacting with a viscous matter fluid in a spatially flat Universe. The matter component represents the baryon and dark matter and it is taken into account, through a bulk…
We investigate the neutrino elastic differential cross-section (NDCS) and corresponding mean free path for neutral current scattering in the dense matter of a neutron star. A wide range of observed neutron star (NS) masses is considered,…
We discuss the bulk viscosity of hot and dense $npe\mu$ matter arising from weak-interaction direct Urca processes. We consider two regimes of interest: (a) the neutrino-transparent regime with $T\leq T_{\rm tr}$ ($T_{\rm tr}\simeq 5\div…
We explore effects of the light vector $U$-boson, which is weakly coupled to nucleons, on the transition density $\rho_{t}$ and pressure $P_{t}$ at the inner edge separating the liquid core from the solid crust of neutron stars. Three…
Neutron stars are one of the most exotic objects in the universe and a unique laboratory to study the nuclear matter above the nuclear saturation density. In this work, we study the equation of state of the nuclear matter within a…
In this work we propose a new method to measure the evolution of the neutron skin thickness between different isotopes. We consider antiproton-nucleus interactions close to the production threshold of ${\Lambda}\overline{\Lambda}$ and…
Neutrino opacities important in the evolution of a proto-neutron star containing quark matter are studied. The results for pure quark matter are compared with limiting expressions previously derived, and are generalized to the temperatures,…
We compute the contribution of phonons to the shear viscosity $\eta$ in superfluid neutron stars, assuming neutron pairing in a $^1S_0$ channel. We use a Boltzmann equation amended by a collision term that takes into account the binary…
The abundance of light nuclei and hyperons, that are produced in stellar environments such as supernova or binary mergers, is calculated within a relativistic mean-field model with density dependent couplings in low-density matter. Five…
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"…
We analyze hyperon and nucleon mass shifts in nuclear matter using chiral perturbation theory. Expressions for the mass shifts that include strong interaction effects at leading order in the density are derived. Corrections to our results…
Uncertainty of the hyperon couplings, in particular, that of the $\Sigma^-$, in dense matter raises the question of the behavior of the electrochemical potential in neutron star matter, which is crucial to the possible presence of the kaon…
We present numerical simulations of stellar core-collapse with spherically symmetric, general relativistic hydrodynamics up to black hole formation. Using the CoCoNuT code, with a newly developed grey leakage scheme for the neutrino…
We analyze the different possibilities for the hadron-quark phase transition occurring in beta-stable matter including hyperons in neutron stars. We use a Brueckner-Hartree-Fock approach including hyperons for the hadronic equation of state…