Skip to Main content Skip to Navigation
Journal articles

PRISM: Recovery of the primordial spectrum from Planck data

Abstract : Aims. The primordial power spectrum describes the initial perturbations that seeded the large-scale structure we observe today. It provides an indirect probe of inflation or other structure-formation mechanisms. In this Letter, we recover the primordial power spectrum from the Planck PR1 dataset, using our recently published algorithm PRISM. Methods. PRISM is a sparsity-based inversion method that aims at recovering features in the primordial power spectrum from the empirical power spectrum of the cosmic microwave background (CMB). This ill-posed inverse problem is regularised using a sparsity prior on features in the primordial power spectrum in a wavelet dictionary. Although this non-parametric method does not assume a strong prior on the shape of the primordial power spectrum, it is able to recover both its general shape and localised features. As a results, this approach presents a reliable way of detecting deviations from the currently favoured scale-invariant spectrum. Results. We applied PRISM to 100 simulated Planck data to investigate its performance on Planck-like data. We then applied PRISM to the Planck PR1 power spectrum to recover the primordial power spectrum. We also tested the algorithm’s ability to recover a small localised feature at k ~ 0.125 Mpc-1, which caused a large dip at ℓ ~ 1800 in the angular power spectrum. Conclusions. We find no significant departures from the fiducial Planck PR1 near scale-invariant primordial power spectrum with As = 2.215 × 10-9 and ns = 0.9624.
Document type :
Journal articles
Complete list of metadatas

Cited literature [6 references]  Display  Hide  Download

https://hal-cea.archives-ouvertes.fr/cea-01290010
Contributor : Edp Sciences <>
Submitted on : Thursday, March 17, 2016 - 2:51:31 PM
Last modification on : Monday, July 6, 2020 - 8:30:03 PM
Long-term archiving on: : Saturday, June 18, 2016 - 5:54:51 PM

File

aa24420-14.pdf
Publication funded by an institution

Identifiers

Citation

François Lanusse, P. Paykari, J.-L. Starck, F. Sureau, J. Bobin, et al.. PRISM: Recovery of the primordial spectrum from Planck data. Astronomy and Astrophysics - A&A, EDP Sciences, 2014, 571, pp.L1. ⟨10.1051/0004-6361/201424420⟩. ⟨cea-01290010⟩

Share

Metrics

Record views

421

Files downloads

686