Constraining the mass of the graviton using coalescing black-hole binaries

TL;DR

This paper demonstrates that gravitational-wave observations of coalescing black-hole binaries, especially using inspiral-merger-ringdown templates, can significantly improve constraints on the graviton's mass compared to previous methods, probing strong-field gravity.

Contribution

It shows that using IMR waveform templates in GW data analysis enhances the accuracy of graviton mass constraints by an order of magnitude over PN templates.

Findings

IMR templates improve graviton mass bounds by about ten times.

GW observatories can set bounds on graviton wavelength several orders better than Solar system tests.

First constraints on graviton mass from the strong-field, dynamical gravity regime.

Abstract

We study how well the mass of the graviton can be constrained from gravitational-wave (GW) observations of coalescing binary black holes. Whereas the previous investigations employed post-Newtonian (PN) templates describing only the inspiral part of the signal, the recent progress in analytical and numerical relativity has provided analytical waveform templates coherently describing the inspiral-merger-ringdown (IMR) signals. We show that a search for binary black holes employing IMR templates will be able to constrain the mass of the graviton much more accurately (about an order of magnitude) than a search employing PN templates. The best expected bound from GW observatories (lambda_g > 7.8 x 10^13 km from Adv. LIGO, lambda_g > 7.1 x 10^14 km from Einstein Telescope, and lambda_g > 5.9 x 10^17 km from LISA) are several orders-of-magnitude better than the best available model-independent bound (lambda_g > 2.8 x 10^12 km, from Solar system tests). Most importantly, GW observations will provide the first constraints from the highly dynamical, strong-field regime of gravity.