Fast Rotating Relativistic Stars: Spectra and Stability without Approximation

TL;DR

This paper investigates the oscillations and stability of relativistic neutron stars using a comprehensive perturbation approach, providing insights into gravitational wave signals and neutron star properties without simplifying approximations.

Contribution

It introduces a detailed, approximation-free analysis of neutron star oscillations and instabilities, including universal relations for gravitational wave asteroseismology.

Findings

Oscillation spectrum of relativistic stars characterized.

Critical values for CFS instability identified.

Universal relations for gravitational wave analysis proposed.

Abstract

We study oscillations and instabilities of relativistic stars using perturbation theory in general relativity and take into account the contribution of a dynamic spacetime. We present the oscillation spectrum as well as the critical values for the onset of the secular CFS instability of neutron stars, and propose universal relations for gravitational wave asteroseismology, which may help constrain the neutron star radius and/or the nuclear equation of state. The results are relevant for all stages during a neutron star's life but especially to nascent or remnant objects following a binary merger.