Hyperonic neutron stars: reconciliation between nuclear properties and NICER and LIGO/VIRGO results

Abstract

Using a extended version of the Quantum Hadrodynamics (QHD), I propose a new microscopic equation of state (EoS) able to correctly reproduce the main properties of symmetric nuclear matter at the saturation density, as well produce massive neutron stars and satisfactory results for the radius and the tidal parameter Λ. I show that even when hyperons are present, this EoS is able to reproduce at least 2.00 solar masses neutron star. The constraints about the radius of a 2.00M⊙ and the minimum mass that enable direct Urca effect are also checked.

Impacts of dark matter on the $f$-mode oscillation of hyperon star

“…Another efficient approach to fix the hyperons-mesons coupling parameters is SU(3) group theory method as given in Refs. [43,44,54,55]. The coupling constants for both scalar and vector mesons are constrained using SU(3) method.…”

Influence of the nuclear symmetry energy slope on observables of compact stars with $Δ$-admixed hypernuclear matter

“…In several previous studies the symmetry energy effects on dense matter has been considered with the matter composition to be purely nucleonic [30][31][32]. However, due to increasing Fermi energy of nucleons interior to NS, the appearance of additional degrees of freedom such as hyperons [28,[33][34][35][36][37][38][39][40][41], ∆-resonances [42][43][44][45][46][47][48][49][50][51][52], meson (π, K, ρ) condensations [53][54][55][56][57][58][59][60] are inevitable or energetically favorable for massive stars as recently observed [16][17][18][19]. Moreover, the appearance of these exotic matter softens the EOS reducing maximum mass of the stars which is in contrary to the observations.…”