Parity violation constraints using 2006-2007 QUaD CMB polarization spectra

TL;DR

This study uses QUaD CMB polarization data to set the most stringent limits yet on parity-violating interactions and cosmological birefringence, finding no significant evidence of such effects.

Contribution

It provides the first tight constraints on electrodynamic parity violation on cosmological scales using CMB polarization spectra.

Findings

Measured polarization rotation angle consistent with zero

Constrained Lorentz violating interactions to less than 2^-43 GeV

Achieved the best limits to date on cosmological parity violation

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 CMB photons. We measure the rotation angle due to such a possible "cosmological birefringence" to be 0.55 deg. +/- 0.82 deg. (random) +/- 0.5 deg. (systematic) using QUaD's 100 and 150 GHz TB and EB spectra over the multipole range 200 < l < 2000, consistent with null, and constrain Lorentz violating interactions to < 2^-43 GeV (68% confidence limit). This is the best constraint to date on electrodynamic parity violation on cosmological scales.