Work

Multimessenger lensing time delay as a probe of the graviton mass

Year: 2025

Type: article

Abstract: Gravitational lensing is a powerful probe of cosmology and astrophysics. With the prospect of the first strongly lensed gravitational waves on the horizon, we highlight an opportunity to test fundamental physics. In this work, we assume a nonzero mass for the graviton, which leads to gravitational waves following timelike geodesics instead of null geodesics. We derive standard gravitational lensing equations, such as the scattering angle, the time-delay between different images and the magnification, which normally rely on the assumption of null geodesics. We show that a single strongly lensed multi-messenger event is enough to constrain the graviton mass to $m< 3 \cdot 10^{-23}$ eV/c$^{2}$. Notably this constraint is independent of the lens model, the waveform model, and of cosmology. Additionally, we explore magnification of images and find that they offer at least three orders of magnitude weaker bounds than the time delay, and have a dependence on the correct modeling of the lens and cosmology.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/2rws-c489

Authors: Elena Colangeli, Charles Dalang, Tessa Baker

Institutions: University of Portsmouth, Queen Mary University of London, Université Paris Sciences et Lettres

Language: English

Topic: Pulsars and Gravitational Waves Research

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Royal Society, European Research Council

Awards: G6473137372, G7684794304