Gravitational waves in massive gravity theories: waveforms, fluxes and constraints from extreme-mass-ratio mergers

TL;DR

This paper analyzes gravitational waveforms from extreme-mass-ratio mergers in massive gravity theories, providing methods to constrain graviton mass and potentially ruling out certain theories based on observational data.

Contribution

It offers a detailed waveform analysis in massive gravity, linking theoretical predictions to observational constraints on graviton mass and black hole mergers.

Findings

Graviton mass constrained to less than ~10^{-23} eV.

Absence of dipolar waves can rule out massive gravity theories.

Waveforms from mergers can test graviton mass in astrophysical settings.

Abstract

Is the graviton massless? This problem was addressed in the literature at a phenomenological level, using modified dispersion relations for gravitational waves, in linearized calculations around flat space. Here, we perform a detailed analysis of the gravitational waveform produced when a small particle plunges or inspirals into a large non-spinning black hole. Our results should presumably also describe the gravitational collapse to black holes and explosive events such as supernovae. In the context of a theory with massive gravitons and screening, merging objects up to $1\,{\rm Gpc}$ away or collapsing stars in the nearby galaxy may be used to constrain the mass of the graviton to be smaller than $\sim 10^{-23}\,{\rm eV}$, with low-frequency detectors. Our results suggest that the absence of dipolar gravitational waves from black hole binaries may be used to rule out entirely such theories.