Year: 2024
Type: article
Abstract: We study the effects of a finite mass for the photon on its propagation in a weak gravitational field. In particular, we analyze the gravitational time delay, also known as the Shapiro effect. We work in isotropic coordinates in the weak-field limit and find that the mass-dependent corrections enhance the gravitational time delay. Doppler-tracking data from the Cassini mission allow us to set an upper bound on the photon mass, namely ${m}_{\ensuremath{\gamma}}<4.9\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}\text{ }\text{ }\mathrm{eV}/{\mathrm{c}}^{2}$ at 95% CL. We also discuss next-generation solar-system tests of general relativity that could improve this upper limit, potentially by a factor of ten. Though not competitive with the currently best limits, our bound is at the ballpark of earlier ones based on the gravitational bending of light by the Sun.
Authors: P. C. Malta, C. A. D. Zarro
Institution: Universidade Federal do Rio de Janeiro
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4404525389