Signature of Lorentz Violation in Continuous Gravitational-Wave Spectra of Ellipsoidal Neutron Stars

TL;DR

This paper investigates how Lorentz-invariance violation could manifest in the gravitational-wave spectra emitted by rotating neutron stars, proposing that higher frequency components could serve as observational signatures of such violations.

Contribution

It introduces a method to identify Lorentz violation effects in continuous gravitational waves from rotating neutron stars using the Standard-Model Extension framework.

Findings

Higher frequency components appear in GW spectra due to Lorentz violation.

Lorentz-invariant NSs do not show these higher frequency components.

Potential observational signatures for testing Lorentz invariance in future GW data.

Abstract

We study effects of Lorentz-invariance violation on the rotation of neutron stars (NSs) in the minimal gravitational Standard-Model Extension framework, and calculate the quadrupole radiation generated by them. Aiming at testing Lorentz invariance with observations of continuous gravitational waves (GWs) from rotating NSs in the future, we compare the GW spectra of a rotating ellipsoidal NS under Lorentz-violating gravity with those of a Lorentz-invariant one. The former are found to possess frequency components higher than the second harmonic, which does not happen for the latter, indicating those higher frequency components to be potential signatures of Lorentz violation in continuous GW spectra of rotating NSs.