The influence of Lorentz violation on UHE photon detection

We show that violation of the Lorentz symmetry in quantum electrodynamics can suppress the rates of the interactions crucial for the formation of photon-induced air showers, such as pair production on nuclei and in the geomagnetic field. As a consequence, the allowed region in the space of Lorentz-violating parameters will be seriously restricted if several photons with energies ≳ 10¹⁹ eV are detected.