Generalized framework for testing gravity with gravitational-wave propagation. I. Formulation

TL;DR

This paper introduces a universal, model-independent framework for testing gravity using gravitational wave propagation, enabling the detection of deviations from general relativity across various theories and sources.

Contribution

It proposes a generalized effective field theory framework for GW propagation and demonstrates how future GW observations can constrain modifications of gravity.

Findings

Framework allows model-independent tests of gravity.

Parameter estimation shows potential to constrain deviations.

Applicable to various cosmological gravity theories.

Abstract

The direct detection of gravitational waves (GW) from merging binary black holes and neutron stars mark the beginning of a new era in gravitational physics, and it brings forth new opportunities to test theories of gravity. To this end, it is crucial to search for anomalous deviations from general relativity in a model-independent way, irrespective of gravity theories, GW sources, and background spacetimes. In this paper, we propose a new universal framework for testing gravity with GW, based on the generalized propagation of a GW in an effective field theory that describes modification of gravity at cosmological scales. Then we perform a parameter estimation study, showing how well the future observation of GW can constrain the model parameters in the generalized models of GW propagation.