Gravitational-Wave Constraints on an Effective Field-Theory Extension of General Relativity

TL;DR

This paper uses gravitational-wave data from LIGO and Virgo to set the first constraints on an effective field-theory extension of General Relativity, focusing on higher-order curvature terms, and discusses future prospects for tighter bounds.

Contribution

It introduces gravitational-wave templates for an extended gravity theory and performs Bayesian tests with real data, establishing initial constraints on new physics at ~150 km scales.

Findings

Data disfavors new physics at ~150 km scales

Developed gravitational-wave templates for extended gravity

Outlined strategies for future constraints with more observations

Abstract

Gravitational-wave observations of coalescing binary systems allow for novel tests of the strong-field regime of gravity. Using data from the Gravitational Wave Open Science Center (GWOSC) of the LIGO and Virgo detectors, we place the first constraints on an effective field-theory based extension of General Relativity in which only higher-order curvature terms are added to the Einstein-Hilbert action. We construct gravitational-wave templates describing the quasi-circular, adiabatic inspiral phase of binary black holes in this extended theory of gravity. Then, after explaining how to properly take into account the region of validity of the effective field theory when performing tests of General Relativity, we perform Bayesian model selection using the two lowest-mass binary black-hole events reported to date by LIGO and Virgo -- GW151226 and GW170608 -- and constrain this theory with respect to General Relativity. We find that these data disfavors the appearance of new physics on distance scales around $\sim 150$ km. Finally, we describe a general strategy for improving constraints as more observations will become available with future detectors on the ground and in space.