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

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 $2.81_{-0.37}^{+0.50}\times {10}^{14}$ GeV and $9.85_{-0.60}^{+0.84}\times {10}^5$ 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.