Solar system vs. gravitational-wave bounds on the graviton mass

TL;DR

This paper compares gravitational-wave and solar system data to set bounds on the graviton mass, finding solar system measurements now provide more stringent limits than gravitational-wave observations.

Contribution

The study revisits and improves the solar system bound on the graviton mass using recent Mars perihelion data, surpassing gravitational-wave bounds.

Findings

Solar system data yields a lower bound on the graviton wavelength of 1.2 to 2.2 x 10^{14} km.

This bound exceeds the gravitational-wave bound by an order of magnitude.

Future improvements could further tighten these bounds.

Abstract

TThe detection of gravitational waves from merging binary black holes has led to a bound on the mass of a hypothetical massive carrier of the gravitational interaction predicted by some modified gravity theories (a massive graviton, for short), corresponding to a bound on the Compton wavelength $\lambda_g > 1.6 \times 10^{13}$ km. This bound is six times more stringent than a 1988 bound inferred from solar-system dynamics. Using 30 years of improvements in solar system data, chiefly from missions involving orbiters and probes of planets from Mercury to Saturn, we revisit this bound. We show that data on the perihelion advance of Mars obtained from the Mars Reconnaissance Orbiter leads to a credible lower bound on $\lambda_g$ between $1.2$ and $2.2 \times 10^{14}$ km, surpassing the gravitational-wave bound by an order of magnitude. We discuss ways in which each of these competing bounds may improve in the future.