Gravitational wave constraints on non-birefringent dispersions of gravitational waves due to Lorentz violations with GWTC-3

TL;DR

This study uses gravitational wave data from GWTC-3 to test for Lorentz violations affecting wave dispersion, finding no evidence and setting constraints on possible Lorentz-violating coefficients.

Contribution

It introduces a method to constrain non-birefringent Lorentz-violating dispersion effects in GWs using GWTC-3 data and the SME framework.

Findings

No evidence of Lorentz violation in GW data

Constraints placed on 25 Lorentz-violating coefficients

Method demonstrated for future tests with GW data

Abstract

The standard model extension (SME) is an effective field theory framework that can be used to study the possible violations of Lorentz symmetry in the gravitational interaction. In the SME's gauge invariant linearized gravity sector, the dispersion relation of GWs is modified, resulting in anisotropy, birefringence, and dispersion effects in the propagation of GWs. In this paper, we mainly focus on the non-birefringent and anisotropic dispersion relation in the propagation of GWs due to the violation of Lorentz symmetry. With the modified dispersion relation, we calculate the corresponding modified waveform of GWs generated by the coalescence of compact binaries. We consider the effects from the operators with the lowest mass dimension $d=6$ in the gauge invariant linearized gravity sector of the SME which are expected to have the dominant Lorentz-violating effect on the propagation of GWs. For this case, the Lorentz-violating effects are presented by 25 coefficients and we constrain them independently by the ``maximal-reach" approach. We use 90 high-confidence GW events in the GWTC-3 catalog and use {\tt Bilby}, an open source software, and {\tt Dynest}, a nested sampling package, to perform parameter estimation with the modified waveform. We do not find any evidence of Lorentz violation in the GWs data and give a $90\%$ confidence interval for each Lorentz violating coefficient.