Probing Lorentz invariance violation with Active Galactic Nuclei and the future Cherenkov Telescope Array
by
Mathieu Chretien(CoPS, Fysikum, Stockholm University)
→
Europe/Stockholm
FA32
FA32
Description
Quantum gravity is a theory attempting to unify general relativity with microscopic physics. Some models predict a Lorentz invariance violation at the Planck scale (1.22×1019 GeV) resulting in modified energy dependent dispersion relations for particles. This enables the possibility of measuring time delays between photons of different energies. In this work we investigate the two first order corrections to the speed of light using active galactic nuclei (AGN) as sources of very high energy photons in the context of the future Cherenkov Telescope Array (CTA). We simulate data from six sources chosen to be representative of AGNs as measured by CTA. As so far, no experiment has claimed the existence of LIV, we generate
data with a negligible effect due to LIV. We perform the first combined likelihood analysis using several AGNs and obtain the limit MQG > 4.74 × 1019 GeV on the
first correction term to the speed of light which is about four times larger than the Planck mass and 22 times larger than the best result obtained by the High Energy
Stereoscopic System (HESS) collaboration with the blazar PKS 2155-304 flare of MJD 53944 (July 28, 2006). We derive a second order limit MQG > 2.49 × 1012
GeV which is about two orders of magnitude larger than the one obtained by HESS collaboration but still far from the Planck scale. These results show the potential
of CTA in probing LIV by combining several observation of AGNs.
