Weak Gravitational Lensing of CMB - Revisit

TL;DR

This paper revisits the weak gravitational lensing effect on the CMB, highlighting how the deflection angle varies with redshift and providing updated power spectra corrections.

Contribution

It introduces a modified calculation of CMB power spectra accounting for redshift-dependent deflection angles, refining previous models.

Findings

Temperature power spectrum correction ~0.01%

Polarization E mode correction ~0.01%

B mode correction ~0.4% up to l=2000

Abstract

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 $l=2000$).