Smoothing methods comparison for CMB E- and B-mode separation

Understand

The anisotropies of the B-mode polarization in the cosmic microwave background radiation play a crucial role for the study of the very early Universe.

• However, in the real observation, the mixture of the E-mode and B-mode can be caused by the partial sky surveys, which must be separated before applied to the cosmological explanation.
• The separation method developed by Smith (\citealt{PhysRevD.74.083002}) has been widely adopted, where the edge of the top-hat mask should be smoothed to avoid the numerical errors.
• In this paper, we compare three different smoothing methods, and investigate the leakage residuals of the E-B mixture.