Year: 2019
Type: article
Abstract: A set of hadronic equations of state (EoSs) derived from relativistic density-functional theory and constrained by terrestrial experiments, astrophysical observations, in particular by the GW170817 event, and chiral effective field theory $(\ensuremath{\chi}\mathrm{EFT})$ of neutron matter is used to explore the sensitivity of the EoS parameterization on the few nuclear-matter characteristics defined at the saturation density. We find that the gross properties of compact stars are most sensitive to the isoscalar skewness coefficient ${Q}_{\text{sat}}$ and the isovector slope coefficient ${L}_{\text{sym}}$ around saturation density, since the higher-order coefficients, such as ${K}_{\text{sym}}$, are fixed by our model. More specifically, (i) among these ${Q}_{\text{sat}}$ is the dominant parameter controlling both the maximum mass and the radii of compact stars while ${L}_{\mathrm{sym}}$ is constrained somewhat by $\ensuremath{\chi}\mathrm{EFT}$ of neutron matter, (ii) massive-enough $(M\ensuremath{\sim}2.0\phantom{\rule{0.16em}{0ex}}{M}_{\ensuremath{\bigodot}})$ compact stars featuring both hyperons and $\mathrm{\ensuremath{\Delta}}$ resonances can be obtained if the value of ${Q}_{\text{sat}}$ is large enough, and (iii) the emergence of $\mathrm{\ensuremath{\Delta}}$'s reduces the radius of a canonical mass $(M\ensuremath{\sim}1.4\phantom{\rule{0.16em}{0ex}}{M}_{\ensuremath{\bigodot}})$ compact star thus easing the tension between the predictions of the relativistic density functionals and the inferences from the x-ray observation of nearby isolated neutron stars.
Source: Physical Review C
Authors: Jia Jie Li, Armen Sedrakian
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Award: G6587340520
OpenAlex ID: W2921976040