Cosmological Constraints on Lorentz Violation in Electrodynamics

Abstract

Infrared, optical, and ultraviolet spectropolarimetry of cosmological sources is used to constrain the pure electromagnetic sector of a general Lorentz-violating standard-model extension. The coefficients for Lorentz violation are bounded to less than 3x10^{-32}.

Comments: 4 pages, accepted for publication in Physical Review Letters