Signals for Lorentz violation in electrodynamics

An investigation is performed of the Lorentz-violating electrodynamics extracted from the renormalizable sector of the general Lorentz- and CPT-violating standard-model extension. Among the unconventional properties of radiation arising from Lorentz violation is birefringence of the vacuum. Limits on the dispersion of light produced by galactic and extragalactic objects provide bounds of $3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}$ on certain coefficients for Lorentz violation in the photon sector. The comparative spectral polarimetry of light from cosmologically distant sources yields stringent constraints of $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}32}.$ All remaining…

• UD
  U.S. Department of Energy

  Awards: FG02-91ER40661, DE-FG02-91ER40661, DE-FG02-, DE-FG02
• NA
  National Aeronautics and Space Administration