New Tests on Lorentz Invariance Violation Using Energy-resolved Polarimetry of Gamma-Ray Bursts

• Published in: The Astrophysical journal Vol. 983; no. 2; pp. 164 - 169
• Main Author: Wei, Jun-Jie
• Format: Journal Article
• Language: English
• Published: The American Astronomical Society 20.04.2025; IOP Publishing
• Subjects: Gamma-ray bursts; Gravitation; Particle astrophysics; Quantum gravity
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/adc4e1

One of the manifestations of Lorentz invariance violation (LIV) is vacuum birefringence, which leads to an energy-dependent rotation of the polarization plane of linearly polarized photons arising from an astrophysical source. Here we use the energy-resolved polarization measurements in the prompt gamma-ray emission of five bright gamma-ray bursts (GRBs) to constrain this vacuum birefringent effect. Our results show that at the 95% confidence level, the birefringent parameter η characterizing the broken degree of Lorentz invariance can be constrained to be ∣ η ∣ < O ( 1 0 − 15 − 1 0 − 16 ) , which represents an improvement of at least 8 orders of magnitude over existing limits from multiband optical polarization observations. Moreover, our constraints are competitive with previous best bounds from the single gamma-ray polarimetry of other GRBs. We emphasize that, thanks to the adoption of the energy-resolved polarimetric data set, our results on η are statistically more robust. Future polarization measurements of GRBs at higher energies and larger distances would further improve LIV limits through the birefringent effect.