Filip Rescic, Luis Recabarren Vergara, Michele Doro, Tomislav Terzić

We show that the GRB 221009A spectrum detected by LHAASO can be used to probe effects of quadratic subluminal Lorentz Invariance Violation (LIV) through the enhancement of the observed flux at the highest energies. In particular, we argue that excesses in the GRB 221009A data currently classified as non-detections at energies $E \gtrsim 30$ TeV warrant further investigation, as they may indicate a recovery of the intrinsic source spectrum consistent with the LIV-induced suppression of $γγ\to e^-e^+$ interactions within the quadratic subluminal scenario. This would increase the accessible parameter space of the energy scale of new physics.