# Testing massive-field modifications of gravity via gravitational waves

## TL;DR

This paper uses gravitational wave data from LIGO-Virgo to test for massive-field modifications of gravity, especially dipole radiation, and places new constraints on Einstein-dilaton-Gauss-Bonnet coupling parameters.

## Contribution

It extends the parametrized post-Einsteinian framework to include massive fields and provides the first constraints on EdGB coupling from gravitational wave observations.

## Key findings

- Constraints on dipole radiation activation in the mass range $10^{-14}$ to $10^{-13}$ eV.
- First 90\% confidence level bounds on EdGB coupling parameter from gravitational wave data.
- Upper limit of $oxed{ ext{~}2.47 ext{ km}}$ on $oxed{ ext{~}
oot{ ext{~}4} ext{~} ext{of } ext{~} ext{ } ext{ extit{ extbf{ ext{alpha}}}_{ ext{EdGB}}}}$ for masses less than $6 imes 10^{-14}$ eV.

## Abstract

The direct detection of gravitational waves now provides a new channel of testing gravity theories. Despite that the parametrized post-Einsteinian framework is a powerful tool to quantitatively investigate effects of modification of gravity theory, the gravitational waveform in this framework is still extendable. One of such extensions is to take into account the gradual activation of dipole radiation due to massive fields, which are still only very weakly constrained if their mass $m$ is greater than $10^{-16}$ eV from pulsar observations. Ground-based gravitational-wave detectors, LIGO, Virgo, and KAGRA, are sensitive to this activation in the mass range, $10^{-14}$ eV $\lesssim m \lesssim 10^{-13}$ eV. Hence, we discuss a dedicated test for dipole radiation due to a massive field using the LIGO-Virgo collaboration's open data. In addition, assuming Einstein-dilaton-Gauss-Bonnet (EdGB) type coupling, we combine the results of the analysis of the binary black hole events to obtain the 90\% confidence level constraints on the coupling parameter $\alpha_{\rm EdGB}$ as $\sqrt{\alpha_{\rm EdGB}} \lesssim 2.47$ km for any mass less than $6 \times 10^{-14}$ eV for the first time, including $\sqrt{\alpha_{\rm EdGB}} \lesssim 1.85$ km in the massless limit.