New constraints on Parity Symmetry from a re-analysis of the WMAP-7 low resolution power spectra

The Parity symmetry of the Cosmic Microwave Background (CMB) pattern as seen by WMAP 7 is tested jointly in temperature and polarization at large angular scale. A Quadratic Maximum Likelihood (QML) estimator is applied to the WMAP 7 year low resolution maps to compute all polarized CMB angular power spectra. The analysis is supported by 10000 realistic Monte-Carlo realizations. We confirm the previously reported Parity anomaly for TT in the range δl = [2, 22] at > 99.5% C.L.. No anomalies have been detected in TT for a wider l range (up to lmax = 40). No violations have been found for EE, TE and BB which we test here for the first time. The cross-spectra TB and EB are found to be consistent with zero. We also forecast Planck capabilities in probing Parity violations on low resolution maps.