Abstract
We constrain parity-violating interactions to the surface of last scattering using spectra from the QUaD experiment’s second and third seasons of observations by searching for a possible systematic rotation of the polarization directions of cosmic microwave background photons. We measure the rotation angle due to such a possible “cosmological birefringence” to be (random) (systematic) using QUaD’s 100 and 150 GHz temperature-curl and gradient-curl spectra over the spectra over the multipole range , consistent with null, and constrain Lorentz-violating interactions to (68% confidence limit). This is the best constraint to date on electrodynamic parity violation on cosmological scales.
- Received 4 November 2008
DOI:https://doi.org/10.1103/PhysRevLett.102.161302
©2009 American Physical Society