Efficiency of pseudospectrum methods for estimation of the cosmic microwave background B -mode power spectrum

The estimation of the B-mode angular power spectrum of polarized anisotropies of the cosmic microwave background is a key step towards a full exploitation of the scientific potential of this probe. In the context of pseudo-spectrum methods the major challenge is related to a contamination of the B-mode spectrum estimate with the residual power of the much larger E-mode. This so-called E-to-B leakage is unavoidably present whenever only an incomplete sky map is available, as is the case for any realistic observation. We find that although all these methods allow us to reduce significantly the level of the E-to-B leakage, it is the method of Smith that at the same time ensures the smallest error bars in all experimental configurations studied here, owing to the fact that it permits straightforwardly an optimization of the sky apodization of the polarization maps used for the estimation. For a satellite-like experiment, this method enables a detection of the B-mode power spectrum at large angular scales but only after appropriate binning. The method of Zhao and Baskaran is a close runner-up in the case of a nearly full-sky coverage.