Ade, Peter A. R. ![]() ![]() |
Abstract
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.
Item Type: | Article |
---|---|
Date Type: | Publication |
Status: | Published |
Schools: | Physics and Astronomy |
Subjects: | Q Science > QB Astronomy Q Science > QC Physics |
Publisher: | EDP Sciences |
ISSN: | 0004-6361 |
Date of Acceptance: | 16 March 2014 |
Last Modified: | 01 Nov 2022 09:58 |
URI: | https://orca.cardiff.ac.uk/id/eprint/89781 |
Citation Data
Cited 101 times in Scopus. View in Scopus. Powered By Scopus® Data
Actions (repository staff only)
![]() |
Edit Item |