Cosmological Signature of New Parity-Violating Interactions

Are there any manifestations of parity violation other than those observed in weak interactions? A map of the cosmic microwave background (CMB) temperature and polarization will provide a new signature of $P$ violation. We examine two classes of $P$-violating interactions that would give rise to such a signature. The first interaction leads to a cosmological birefringence, possibly driven by quintessence. The other interaction leads to an asymmetry in the amplitude of right- versus left-handed gravitational waves produced during inflation. The Planck Surveyor should improve upon the current sensitivity to birefringence. While the primordial effect would most likely elude detection by MAP and Planck, it may be detectable with a future dedicated CMB polarization experiment.