Constraining the anomalous coupling of gravitational waves with double pulsar

TL;DR

This paper uses precise measurements of the Double Pulsar to tightly constrain the possible deviation of gravitational wave coupling from Newton's constant, testing modified gravity theories.

Contribution

It provides the most stringent constraint to date on the ratio of gravitational wave coupling to Newton's constant using binary pulsar data.

Findings

The ratio G_{gw}/G_N is constrained to within 10^{-4}.

The results improve previous bounds by two orders of magnitude.

Implications for modified gravity models are discussed.

Abstract

We revisit the decay of the orbital period in binary systems that occurs due to the emission of gravitational waves in the context of modified gravity models where the coupling $G_{gw}$ between matter and on-shell gravitons is allowed to differ from the Newton constant $G_N$. Using the most precise orbital parameters of binary pulsars, those of the Double Pulsar, we constrain the ratio $G_{gw}/G_N$ to the level of $10^{-4}$, improving by two orders of magnitude the present bound on this quantity.