Physical acceptability conditions for realistic neutron star equations of state

TL;DR

This study evaluates 37 realistic neutron star equations of state against physical acceptability conditions, revealing violations of causality, energy conditions, and instabilities in certain models.

Contribution

It systematically tests a broad set of dense matter equations of state for physical viability within relativistic stellar models.

Findings

Some non-relativistic equations violate causality.

Certain models breach the dominant energy condition.

Adiabatic instabilities occur in the inner crust for all equations considered.

Abstract

We select 37 most common and realistic dense matter equation of states to integrate the general relativistic stellar structure equations for static spherically symmetric matter configurations. For all these models, we check the compliance of the acceptability conditions that every stellar model should satisfy. It was found that some of the non-relativistic equation of states violate the causality and/or the dominant energy condition and that adiabatic instabilities appear in the inner crust for all equation of state considered.