Asset Publisher

Planck 2013 results. XVII. Gravitational lensing by large-scale structure

Planck 2013 results. XVII. Gravitational lensing by large-scale structure

Publication date: 29 October 2014

Authors: Planck Collaboration

Journal: Astronomy & Astrophysics
Volume: 571, November 2014
Page: A17
Year: 2014

Copyright: ESO, 2014

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.

Link to publication
Last Update: Sep 1, 2019 8:31:52 AM
5-Jun-2020 10:11 UT

ShortUrl Portlet

Shortcut URL

https://sci.esa.int/s/wKdOPbW

Images And Videos

Related Publications

Related Links

See Also

Documentation