Constraints on Lorentz invariance violation from HAWC observations of gamma rays above 100 TeV

TL;DR

This paper uses high-energy gamma-ray observations from HAWC to set new, stringent limits on Lorentz invariance violation, surpassing previous constraints by over an order of magnitude.

Contribution

The study provides the strongest constraints to date on LIV energy scale using 100 TeV gamma-ray data from multiple astrophysical sources.

Findings

Excludes LIV energy scale below 2.2×10^{31} eV.

Detects 100 TeV gamma-ray emission from at least four sources.

Improves previous LIV limits by 1-2 orders of magnitude.

Abstract

Due to the high energies and long distances to the sources, astrophysical observations provide a unique opportunity to test possible signatures of Lorentz invariance violation (LIV). Superluminal LIV enables the decay of photons at high energy. The High Altitude Water Cherenkov (HAWC) Observatory is among the most sensitive gamma-ray instruments currently operating above 10 TeV. HAWC finds evidence of 100 TeV photon emission from at least four astrophysical sources. These observations exclude, for the strongest of the limits set, the LIV energy scale to $2.2\times10^{31}$ eV, over 1800 times the Planck energy and an improvement of 1 to 2 orders of magnitude over previous limits.