Testing ParityViolating Interactions with CMB Experiments
Abstract
The Standard Model (SM) violates parity (P) within the weak sector, presumably because it is a lowenergy limit of some grand unified theory. Since physics beyond the SM is required to explain the observed cosmology, there is a possibility that nature also violates parity through gravity or other yet undiscovered sectors. Considerable interest has been dedicated to two classes of Pviolating interactions beyond the SM: chiral gravity, with parity odd ChernSimons terms in the action, and quintessence models that couple to the pseudoscalar of electromagnetism, manifesting themselves as cosmological birefringence. These mechanisms can produce nonvanishing Pbreaking correlations in CMB temperature and polarization maps, opening the possibility of measurement through cosmological experiments.
We develop the fullsky formalism for estimating the amount of directiondependent rotation of the CMB polarization due to quintessence effects, and we calculate constraints on the rotation angle multipoles for different instrumental resolutions and noise levels. We use a similar formalism to calculate the constraints on chirality of primordial gravitational waves that could be obtained with different instruments. Finally, we combine the two Pviolating mechanisms and calculate the constraints on the joint parameter space. We find that data with WMAP sensitivity yield no constraint on gravitational chirality, and put an upper limit of 2 degrees on uniform rotation from quintessence, consistent with previous results. We explore how the allowed parameter space changes in the case of nondetection with Planck, SPIDER, and CMBPol.
 Publication:

American Astronomical Society Meeting Abstracts #215
 Pub Date:
 January 2010
 Bibcode:
 2010AAS...21540703G