Polarization Measurements as a Probe of Axion-Photon Coupling: a Study of GRB 221009A

TL;DR

This study derives new bounds on axion-photon coupling using polarization data from GRB 221009A, employing full Stokes parameter calculations, and explores implications for ALP dark matter within specific mass ranges.

Contribution

First to derive axion-photon coupling bounds from GRB polarization measurements using comprehensive Stokes parameter analysis.

Findings

Limits on axion-photon coupling are competitive with other probes.

Constraints are relevant for ALP dark matter in the mass range 10^{-9} to 10^{-8} eV.

Astrophysical uncertainties are considered in the analysis.

Abstract

Axion Like Particles (ALPs) can be produced in Gamma Ray Bursts, altering the polarization of the electromagnetic emission in these events. For the first time, we derive bounds on the axion-photon coupling from polarization measurements of GRB 221009A, performing a full calculation of the Stokes parameters, as it is typically done in the astrophysics community. Within astrophysical uncertainties, our limits on the axion-photon coupling are competitive with complementary probes in the axion mass range $10^{-9}$ eV $\lesssim m_a \lesssim 10^{-8}$ eV, further allowing to probe motivated parameter space of ALP dark matter.