{mosimage}Three months at Hamburg University, working till 10 p.m. with professor Günter Sigl, and never a single drop of lager. That’s how {cb_profile=galaverni}Matteo Galaverni{/cb_profile}, Phd-student at IASF-BO, has spent his time in Germany. Studying the highest energy cosmic rays captured by the Pierre Auger Observatory. More energetic than anything available on the Earth, even once [[LHC]] will be running at full power, the interaction of these cosmic rays with the low energy photons of the cosmic microwave background is the key to check whether Einstein’s relativity and Lorentz’s symmetry hold. And the answer is yes, they do! Galaverni’s and Sigl’s paper, Lorentz Violation and Ultrahigh-Energy Photons, already available on the web, has just been submitted to Physical Review.