Planck 2013 results. XVII. Gravitational lensing by large-scale structure
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Gravitational lensing: weakMethods: data analysisCosmic background radiationLarge-scale structure of Universe
Ade, P. A., Aghanim, N., Armitage-Caplan, C., Arnaud, M., Ashdown, M., Atrio-Barandela, F., ... & Bartlett, J. G. (2014). Planck 2013 results. XVII. Gravitational lensing by large-scale structure. Astronomy & Astrophysics, 571, A17. [https://doi.org/10.1051/0004-6361/201321543]
SponsorshipEuropean Space Agency; Centre National D'etudes Spatiales; CNRS/INSU-IN2P3-INP (France); Italian Space Agency (ASI); Istituto Nazionale Astrofisica (INAF); Italian National Research Council; National Aeronautics & Space Administration (NASA); United States Department of Energy (DOE); UKSA (UK); Consejo Superior de Investigaciones Cientificas (CSIC); Spanish Government; JA (Spain); RES (Spain); Finnish Funding Agency for Technology & Innovation (TEKES); AoF (Finland); CSC (Finland); Helmholtz Association; German Aerospace Centre (DLR); Max Planck Society; CSA (Canada); DTU Space (Denmark); SER/SSO (Switzerland); RCN (Norway); Science Foundation Ireland; Portuguese Foundation for Science and Technology; European Union (EU); United States Department of Energy (DOE) DE-AC02-05CH11231; IN2P3 Computer Center; Science & Technology Facilities Council (STFC) ST/I000976/1 ST/K003674/1 ST/H001239/1 ST/J000388/1 ST/M007685/1 ST/K00106X/1 ST/K000985/1 ST/K001051/1 ST/I005765/1 ST/L001314/1 ST/K004131/1 ST/K002805/1 ST/K00333X/1 ST/H008586/1 ST/J004812/1 ST/G003874/1 ST/K002899/1 ST/J005673/1 ST/I002006/1 ST/L000768/1 ST/J001368/1
On the arcminute angular scales probed by Planck, the cosmic microwave background (CMB) anisotropies are gently perturbed by gravitational lensing. Here we present a detailed study of this effect, detecting lensing independently in the 100, 143, and 217 GHz frequency bands with an overall significance of greater than 25σ. We use thetemperature-gradient correlations induced by lensing to reconstruct a (noisy) map of the CMB lensing potential, which provides an integrated measure of the mass distribution back to the CMB last-scattering surface. Our lensing potential map is significantly correlated with other tracers of mass, a fact which we demonstrate using several representative tracers of large-scale structure. We estimate the power spectrum of the lensing potential, finding generally good agreement with expectations from the best-fitting ΛCDM model for the Planck temperature power spectrum, showing that this measurement at z = 1100 correctly predicts the properties of the lower-redshift, later-time structures which source the lensing potential. When combined with the temperature power spectrum, our measurement provides degeneracy-breaking power for parameter constraints; it improves CMB-alone constraints on curvature by a factor of two and also partly breaks the degeneracy between the amplitude of the primordial perturbation power spectrum and the optical depth to reionization, allowing a measurement of the optical depth to reionization which is independent of large-scale polarization data. Discarding scale information, our measurement corresponds to a 4% constraint on the amplitude of the lensing potential power spectrum, or a 2% constraint on the root-mean-squared amplitude of matter fluctuations at z ~ 2.