Future tests of relativity, with cosmic rays or in the lab

Abstract

Experimental tests of Lorentz violation are important to our understanding of fundamental physics, and interest in them has picked up a great deal in the twenty-first century. For some of the most natural forms of Lorentz violation involving electrons and positrons, there are competing bounds coming from high-energy astrophysical observations and laboratory tests with optical atomic clocks. I discuss the advantages and limitations of both these approaches and how they may evolve in the future.