Constraining Lorentz and parity violations in gravity with multiband gravitational wave observations

TL;DR

Future multi-band gravitational wave observations from ground and space detectors can greatly improve constraints on Lorentz and parity violations in gravity, enabling more precise tests of general relativity across different binary systems.

Contribution

This paper demonstrates that multi-band gravitational wave observations can significantly tighten constraints on Lorentz and parity violations, especially for different frequency-dependent modifications, using Bayesian analysis of simulated events.

Findings

Multi-band observations improve constraints on Lorentz and parity violations by several orders of magnitude.

High-SNR events like GW250114 provide strong limits on high-frequency modifications.

Massive binary systems like GW231123 yield better constraints on low-frequency effects.

Abstract

This study evaluates the capability of future multi-band observations of gravitational waves emitted from binary black hole coalescences, utilizing joint third-generation ground-based (CE, ET) and space-based (LISA, Taiji, TianQin) detector networks, to constrain parity and Lorentz symmetry violations in the gravitational sector. We model these effects through a parameterized waveform framework that incorporates a set of parameters that quantify potential deviations from general relativity. The frequency-dependence of their effects is described by power-law indices $\beta$ (i.e., $\beta_{\bar \nu}$, $\beta_{\bar \mu}$, $\beta_{\nu}$, and $\beta_{\mu}$). By analyzing events such as a high-signal noise ratio (SNR) "golden event" like GW250114 and a massive binary system like GW231123 (total mass $190-265 M_\odot$) using two networks of ground- and space-based detectors, we demonstrate that multi-band observations can significantly improve the current constraints on Lorentz and parity violations by several order of magnitude, for both high-frequency ($\beta > 0$) and low-frequency ($\beta < 0$) modifications. Our Bayesian analysis reveals that while the exceptional SNR of the GW250114-like event yields superior constraints for high-frequency modifications ($\beta > 0$), the massive nature of GW231123 provides more stringent limits for low-frequency effects ($\beta < 0$). This work highlights the critical value of future multi-band gravitational wave astronomy for conducting precision tests of general relativity across diverse binary populations.