Testing the nature of gravitational wave propagation using dark sirens and galaxy catalogues

TL;DR

This paper extends a gravitational wave analysis code to test deviations from General Relativity using dark sirens and galaxy catalogues, providing new constraints on gravity and cosmological parameters from GWTC-3 data.

Contribution

The authors develop and apply an extended analysis pipeline for dark sirens, incorporating galaxy catalogues and mass distributions to constrain gravity deviations and cosmology.

Findings

Reanalyzed 46 GWTC-3 events with the new pipeline.

Obtained joint constraints on H0 and gravity deviations.

Prepared for application to future O4 data.

Abstract

The dark sirens method enables us to use gravitational wave events without electromagnetic counterparts as tools for cosmology and tests of gravity. Furthermore, the dark sirens analysis code gwcosmo can now robustly account for information coming from both galaxy catalogues and the compact object mass distribution. We present here an extension of the gwcosmo code and methodology to constrain parameterized deviations from General Relativity that affect the propagation of gravitational waves. We show results of our analysis using data from the GWTC-3 gravitational wave catalogues, in preparation for application to the O4 observing run. After testing our pipelines using the First Two Years mock data set, we reanalyse 46 events from GWTC-3, and combine the posterior for BBH and NSBH sampling results for the first time. We obtain joint constraints on H0 and parameterized deviations from General Relativity in the Power Law + Peak BBH population model. With increased galaxy catalogue support in the future, our work sets the stage for dark sirens to become a powerful tool for testing gravity.