Maximum mass and stability of differentially rotating neutrons stars

TL;DR

This study investigates the stability of differentially rotating neutron stars with a polytropic equation of state, revealing that many hypermassive, quasi-toroidal configurations are dynamically stable, impacting understanding of neutron star formation and mergers.

Contribution

It provides new insights into the stability conditions of differentially rotating neutron stars with quasi-toroidal shapes using a specific equation of state.

Findings

Hypermassive, quasi-toroidal neutron stars are dynamically stable against quasi-radial perturbations.

Stability persists over a wide range of parameters.

Implications for newly born neutron stars and binary mergers.

Abstract

We present our study of stability of differentially rotating, axisymmetric neutron stars described by a polytropic equation of state with $\Gamma = 2$. We focus on quasi-toroidal solutions with a degree of differential rotation $\widetilde A=1$. Our results show that for a wide range of parameters hypermassive, quasi-toroidal neutron stars are dynamically stable against quasi-radial perturbations, which may have implications for newly born neutron stars and binary neutron stars mergers.