Explanation of the very-high-energy emission from GRB221009A

Very recently the LHAASO experiment has detected the gamma ray burst GRB221009A with a photon very-high-energy tail extending up to 18 TeV. Soon thereafter Carpet-2 at Baksan Neutrino Observatory has observed an air shower consistent with being caused by a photon of energy $251 \, {\rm TeV}$ from the same GRB. These findings provide a strong hint both at the existence of axion-like-particles (ALPs) with mass $m_a \simeq10^{-10} \, {\rm eV}$ and two-photon coupling $g_{a \gamma \gamma} \simeq 5 \times 10^{-12} \, {\rm GeV}^{- 1}$ and at a Lorentz Invariance Violation at $251 \, {\rm TeV}$. Our ALP parameters are consistent with all available constraints, and these ALPs are good candidates for cold dark matter.