Overview
- The gamma-ray burst GRB 221009A, nicknamed BOAT, erupted on Oct. 9, 2022 and produced a flood of photons that included a roughly 300‑tera‑electron‑volt photon detected by Russia’s Carpet detector.
- Under standard physics that photon should have been removed by pair production with cosmic microwave background photons during its roughly two‑billion‑light‑year trip, making its arrival at Earth puzzling.
- A new paper by Giorgio Galanti, Marco Roncadelli and colleagues, posted on arXiv and accepted by Physical Review Letters, proposes that the photon converted into an axion-like particle, traveled unabsorbed, and reconverted to a photon near the Milky Way aided by a possible high‑energy violation of Lorentz invariance.
- The model predicts the ultrahigh‑energy photon would arrive about one hour after lower‑energy photons, and that timing matches reports from a Chinese observatory followed an hour later by Carpet’s detection, but the explanation remains provisional and requires independent observational checks and scrutiny of instrument or astrophysical alternatives.
- If confirmed, the mechanism would provide a way to study physics at energies far beyond Earth accelerators by using the cosmos as a laboratory, while also testing the existence of axion-like particles and possible limits of Einstein’s special relativity.