Imposing multi-physics constraints at different densities on the Neutron Star Equation of State

TL;DR

This paper constrains the neutron star equation of state across various densities by integrating multi-physics data and theoretical models, enhancing understanding of dense nuclear matter and its astrophysical implications.

Contribution

It introduces a novel multi-physics constraint scheme within the Relativistic Mean Field model to refine the neutron star equation of state across different density regimes.

Findings

Constraints from nuclear experiments limit the EOS at nuclear densities.

Astrophysical observations further restrict the EOS at higher densities.

Correlations between nuclear properties and neutron star observables are identified.

Abstract

Neutron star matter spans a wide range of densities, from that of nuclei at the surface to exceeding several times normal nuclear matter density in the core. While terrestrial experiments, such as nuclear or heavy-ion collision experiments, provide clues about the behaviour of dense nuclear matter, one must resort to theoretical models of neutron star matter to extrapolate to higher density and finite neutron/proton asymmetry relevant for neutron stars. In this work, we explore the parameter space within the framework of the Relativistic Mean Field model allowed by present uncertainties compatible with state-of-the-art experimental data. We apply a cut-off filter scheme to constrain the parameter space using multi-physics constraints at different density regimes: chiral effective field theory, nuclear and heavy-ion collision data as well as multi-messenger astrophysical observations of neutron stars. Using the results of the study, we investigate possible correlations between nuclear and astrophysical observables.