COSMIC MICROWAVE BACKGROUND LENSING WITH THE PLANCK MISSION

The Planck space mission should provide sufficiently low-noise level, hight resolution data to allow the first measurement of the weak gravitational lensing effect imprinted in the CMB maps by the intervening large scale structures. The exploitation of the CMB lensing information can significantly improve the Planck mission sensitivity to cosmological parameters. After a brief review of the CMB lensing and its signatures on the primary CMB observables, we highlight the twofold relevance of extracting the CMB lensing, which is both a contaminant of the primary CMB and a valuable probe of the large-scale structures. The statistical methods which exist in the literature for its reconstruction are presented, focusing on an application to the Planck experiment. Its capability to extract the CMB lensing and the robustness of this measurement to instrument systematics and astrophysical foregrounds are discussed.