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

TL;DR

This study searches for Lorentz invariance violation using spectral lag data from GRB 190114C, employing a profile likelihood approach to handle nuisance parameters, and finds constraints on the LIV energy scale consistent with previous Bayesian estimates.

Contribution

It introduces a frequentist profile likelihood method to analyze spectral lag data for LIV, providing results that align with prior Bayesian analyses.

Findings

Constraints on LIV energy scale below the Planck scale

Consistent results with previous Bayesian estimates

Identification of global minima in the chi-squared analysis

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.