Weak Gravitational Lensing of CMB - Revisit
  In this paper, we revisit the weak gravitational lensing of CMB. The key
point is that the deflection angle of CMB photon varies with the redshift. From
this we obtain a set of modified power spectra. Compared with the ones
calculated before, the temperature, the polarization E mode and the cross power
spectra correction are of the order $0.01 %$, while the polarization B mode
correction is about $0.4 %$ (to $l=2000$).
