The Equation of State of Nuclear Matter : from Finite Nuclei to Neutron Stars

TL;DR

This paper explores the correlations between neutron star observables like tidal deformability and nuclear properties such as neutron skin thickness, using various nuclear equations of state to understand their interdependence and implications for nuclear and astrophysical phenomena.

Contribution

It systematically analyzes the correlations between neutron star and nuclear observables across multiple theoretical models of nuclear equations of state.

Findings

Strong correlation between tidal deformability and neutron star radius.

Weak correlation between neutron skin thickness and symmetry energy stiffness.

Correlation depends on the set of equations of state used.

Abstract

{\it Background.} We investigate possible correlations between neutron star observables and properties of atomic nuclei. Particularly, we explore how the tidal deformability of a 1.4 solar mass neutron star, $M_{1.4}$, and the neutron skin thickness of ${^{48}}$Ca and ${^{208}}$Pb are related to the stellar radius and the stiffness of the symmetry energy. {\it Methods.} We examine a large set of nuclear equations of state based on phenomenological models (Skyrme, NLWM, DDM) and {\it ab-initio} theoretical methods (BBG, Dirac-Brueckner, Variational, Quantum Monte Carlo). {\it Results.} We find strong correlations between tidal deformability and NS radius, whereas a weaker correlation does exist with the stiffness of the symmetry energy. Regarding the neutron skin thickness, weak correlations appear both with the stiffness of the symmetry energy, and the radius of a $M_{1.4}$. {\it Conclusion.} The tidal deformability of a $M_{1.4}$ and the neutron-skin thickness of atomic nuclei show some degree of correlation with nuclear and astrophysical observables, which however depends on the ensemble of adopted EoS.