Revisiting Lorentz invariance violation from GRB 221009A

As a potential consequence of Lorentz invariance violation~(LIV), threshold anomalies open a window to study LIV. Recently the Large High Altitude Air Shower Observatory~(LHAASO) reported that more than 5000 photons from GRB 221009A have been observed with energies above 500~GeV and up to $18~\text{TeV}$. In the literature, it is suggested that this observation may have tension with the standard model result because extragalactic background light~(EBL) can prevent photons around 18~TeV from reaching the earth and that LIV induced threshold anomalies might be able to explain the observation. In this work we further study this proposal with more detailed numerical calculation for different LIV scales and redshifts of the sources. We find that GRB 221009A is a rather unique opportunity to search LIV, and a LIV scale $E_\text{LIV} \lesssim E_\text{Planck}\approx 1.22\times 10^{19}~\text{GeV}$ is feasible to the observation of GRB 221009A on 9 October, 2022.