Role of vector self-interaction in Neutron Star properties

TL;DR

This paper investigates how vector self-interaction in the Relativistic Mean Field model influences neutron star properties and their correlations with nuclear parameters, clarifying the physical nature of these correlations.

Contribution

It demonstrates the role of vector self-interaction in controlling neutron star observables and their correlations with nuclear saturation parameters, using recent astrophysical data.

Findings

Vector self-interaction affects high-density equation of state properties.

It governs correlations between nuclear parameters and neutron star observables.

Limits on vector self-interaction strength are derived from astrophysical data.

Abstract

Previous studies have claimed that there exist correlations among certain nuclear saturation parameters and neutron star observables, such as the slope of the symmetry energy and the radius of a $1.4M_{\odot}$ neutron star. However, it is not clear whether such correlations are physical or spurious, as they are not observed universally for all equation of state models. In this work, we probe the role of vector self-interaction within the framework of the Relativistic Mean Field model and its role in governing the observable stellar properties and their correlations with nuclear parameters. We confirm that the effect of this term is not only to control the high density properties of the equation of state but also to govern such correlations. We also impose a limit on the maximum strength of the vector self-interaction using recent astrophysical data.