Kostelecký, V. AlanMewes, Matthew2004-12-032004-12-0320012001http://hdl.handle.net/2003/189510.17877/DE290R-4663enThe American Physical SocietyPhysical Review Letters530Cosmological Constraints on Lorentz Violation in Electrodynamics10.1103/PhysRevLett.87.251304article (journal)