Search for Lorentz Invariance Violation effects with PKS 2155-304 flaring period in 2006 by H.E.S.S

TL;DR

This study analyzes high-energy photon data from PKS 2155-304 to search for energy-dependent time-lags that could indicate Lorentz Invariance Violation, setting a new stringent limit on Quantum Gravity effects.

Contribution

It presents the first detailed analysis of Lorentz Invariance Violation effects using PKS 2155-304 data from H.E.S.S., establishing the most restrictive limit to date.

Findings

95% confidence limit on Quantum Gravity energy scale: 7x10^17 GeV

No significant energy-dependent time-lags detected

Methodology combining Cross-Correlation and Wavelet Transform

Abstract

Highly energetic, variable and distant sources such as Active Galactic Nuclei provide a good opportunity to evaluate effects due to the emission and the propagation of high energy photons. In this note, a study of possible energy-dependent time-lags with PKS 2155-304 light curve as measured by H.E.S.S. in July 2006 is presented. These time-lags could either come from the emission processes or also sign a Lorentz Symmetry breaking as predicted in some Quantum Gravity models. A Cross-Correlation function and a Wavelet Transform were used to measure the time-lags. The 95% Confidence Limit on the Quantum Gravity energy scale based on the statistical and systematic error evaluation was found to be 7x10^17 GeV considering a linear correction in the standard photon dispersion relations and assuming that emission-induced time-lags are negligible. For now, this limit is the best ever obtained with a blazar.