Stiffness effects on the dynamics of the bar-mode instability of Neutron Stars in full General Relativity

TL;DR

This paper investigates how the stiffness of the equation of state influences the development of the bar-mode instability in rapidly rotating neutron stars within full General Relativity, revealing how the instability threshold varies with stiffness.

Contribution

It provides new insights into the relationship between equation of state stiffness and the onset of bar-mode instability in neutron stars in a relativistic framework.

Findings

Threshold for instability varies with stiffness parameter b3.

Higher stiffness tends to increase the stability of neutron stars.

Results include two realistic equations of state at high densities.

Abstract

We present results on the effect of the stiffness of the equation of state on the dynamical bar-mode instability in rapidly rotating polytropic models of neutron stars in full General Relativity. We determine the change in the threshold for the emergence of the instability for a range of the adiabatic $\Gamma$ index from 2.0 to 3.0, including two values chosen to mimic more realistic equations of state at high densities.