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

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 gravitational waves (GWs) is modified, resulting in anisotropy, birefringence, and dispersion effects in the propagation of GWs. In this paper, we mainly focus on the nonbirefringent 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 1/4 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 BILBY, an open source software, and DYNESTY, 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.

Automated summary

The standard model extension (SME) is used to study the violations of Lorentz symmetry in gravitational interactions. This study focuses on the modified dispersion relation of gravitational waves (GWs) due to Lorentz violation, and calculates the modified waveforms generated by compact binary mergers. By analyzing 90 GW events and employing parameter estimation, no evidence of Lorentz violation in GW data is found, and 90% confidence intervals for each Lorentz violating coefficient are provided.