Radial oscillations in neutron stars from QCD

TL;DR

This paper investigates the stability of neutron stars with quark matter cores using QCD-based equations of state, revealing how violations of the conformal bound affect their oscillation stability and mass-radius relationships.

Contribution

It introduces QCD-derived equations of state to analyze neutron star stability, highlighting the impact of conformal bound violations on star oscillations and stability.

Findings

Neutron stars with quark cores can become dynamically unstable due to large oscillations.

Violations of the conformal bound influence the stability and mass-radius relations.

Some neutron star configurations are unstable near the core due to radial oscillations.

Abstract

We study the stability against infinitesimal radial oscillations of neutron stars generated by a set of equations of state obtained from first-principle calculations in cold and dense QCD and constrained by observational data. We consider mild and large violations of the conformal bound, $c_{s} = 1/\sqrt{3}$, in stars that can possibly contain a quark matter core. Some neutron star families in the mass-radius diagram become dynamically unstable due to large oscillation amplitudes near the core.