Limits on an Energy Dependence of the Speed of Light from a Flare of the Active Galaxy PKS 2155-304
Limits on an Energy Dependence of the Speed of Light from a Flare of the Active Galaxy PKS 2155-304
In the past few decades, several models have predicted an energy dependence of the speed of light in the context of quantum gravity. For cosmological sources such as active galaxies, this minuscule effect can add up to measurable photon-energy dependent time lags. In this Letter a search for such time …