Constraints on parity and Lorentz violations from gravitational waves: a comparison between single-parameter and multi-parameter analysis

TL;DR

This paper compares single-parameter and multi-parameter analyses of gravitational wave data to test for parity and Lorentz violations, finding that single-parameter constraints remain robust even when multiple deviations are considered.

Contribution

The study introduces multi-parameter GW waveform models for parity and Lorentz violations and compares their constraints with traditional single-parameter methods.

Findings

Multi-parameter constraints are comparable to single-parameter results.

Degeneracies can occur between parameters in multi-parameter models.

Single-parameter tests are robust for current GW data.

Abstract

The growing catalog of gravitational wave (GW) detections by the LIGO-Virgo-KAGRA Collaboration enables increasingly stringent tests of general relativity, particularly regarding possible parity and Lorentz violations. While most current analyses employ single-parameter methods, varying one deformation parameter at a time, modified gravity theories often predict multiple, coexisting deviations. In this work, we construct four specific multi-parameter GW waveform models incorporating parity- and Lorentz-violating effects and perform full Bayesian parameter estimation to compare multi-parameter and single-parameter constraints. We find that including multiple deformation parameters yields constraints on individual parameters that are generally comparable to those from single-parameter analyses, despite one specific model showing a degeneracy between the deformation parameters. Our results support the robustness of single-parameter tests for parity and Lorentz symmetry of gravity in current and future GW observations.