Constraining the Mass of the Photon with Gamma-Ray Bursts

TL;DR

This paper uses gamma-ray burst observations to set new, tighter constraints on the photon mass, testing fundamental physics principles like Einstein's special relativity.

Contribution

It introduces a novel method of constraining photon mass using early time radio afterglow and multi-band radio peaks from GRBs, improving previous limits.

Findings

Photon mass upper limit improved by nearly half an order of magnitude.

Radio observations from GRBs provide effective constraints on photon mass.

Results support the massless photon assumption in fundamental physics.

Abstract

One of the cornerstones of modern physics is Einstein's special relativity, with its constant speed of light and zero photon mass assumptions. Constraint on the rest mass m_{\gamma} of photons is a fundamental way to test Einstein's theory, as well as other essential electromagnetic and particle theories. Since non-zero photon mass can give rise to frequency-(or energy-) dependent dispersions, measuring the time delay of photons with different frequencies emitted from explosive astrophysical events is an important and model-independent method to put such a constraint. The cosmological gamma-ray bursts (GRBs), with short time scales, high redshifts as well as broadband prompt and afterglow emissions, provide an ideal testbed for m_{\gamma} constraints. In this paper we calculate the upper limits of the photon mass with GRB early time radio afterglow observations as well as multi-band radio peaks, thus improve the results of Schaefer (1999) by nearly half an order of magnitude.