Weak Lensing of the CMB by Large-Scale Structure

Abstract

Several recent papers have studied lensing of the CMB by large-scale structures, which probes the projected matter distribution from $z=10^3$ to $z\simeq 0$. This interest is motivated in part by upcoming high resolution, high sensitivity CMB experiments, such as APEX/SZ, ACT, SPT or Planck, which should be sensitive to lensing. In this paper we examine the reconstruction of the large-scale dark matter distribution from lensed CMB temperature anisotropies. We go beyond previous work in using numerical simulations to include higher order, non-Gaussian effects and study how well the quadratic estimator of \cite{Hu01a} is able to recover the input field. We also study contamination by kinetic Sunyaev-Zel'dovich signals, which is spectrally indistinguishable from lensed CMB anisotropies. We finish by estimating the sensitivity of the previously cited experiments.