Search for Lorentz Invariance Violation with spectral lags of GRB 190114C using profile likelihood

Abstract

We search for Lorentz invariance violation (LIV) by re-analyzing the spectral lag data for GRB 190114C from Fermi-GBM using frequentist analysis, where we deal with the astrophysical nuisance parameters using profile likelihood. For this use case, we find a global minima for the $\chi^2$ as a function of energy scale of LIV ($E_{QG}$), well below the Planck scale. The best-fit $1\sigma$ central intervals for $E_{QG}$ are given by $2.81^{+0.50}_{-0.37}\times 10^{14}$ GeV and $9.85^{+0.84}_{-0.60}\times 10^{5}$ GeV for linear and quadratic LIV, respectively, and agree with the Bayesian estimates obtained so far in a previous work. Therefore, the results from the frequentist analysis of GRB 190114C agree with Bayesian analysis.