The astrophysical hunt for photon dispersion

The question if the photon velocity varies with its energy has fundamental consequences for physics. The natural way to search for this effect is to observe distant, variable, high energy phenomena in the Universe. I will review the possible objects and their properties, and then summarize the current observational constraints. Finally, I will describe the possible future experiments that may lead to detection of photon dispersion.

E. Czuchry, E. Infeld, W. Piechocki, A. Pollo