# Planck 2018 results

“Planck 2018 results” (2021), by N. Aghanim et al. Physics and Astronomy research paper. Original abstract below, unchanged. No free PDF was found.

- Authors: N. Aghanim, Y. Akrami, M. Ashdown, J. Aumont, Carlo Baccigalupi, M. Ballardini, Anthony J. Banday, R. Belén Barreiro, N. Bartolo, S. Basak et al.
- Published: August 1, 2021
- Field: Physics and Astronomy
- DOI: https://doi.org/10.1051/0004-6361/201833910e
- Source: https://doi.org/10.1051/0004-6361/201833910e

## Abstract

In the original version, the bounds given in Eqs. (87a) and (87b) on the contribution to the early-time optical depth, (15,30), contained a numerical error in deriving the 95th percentile from the Monte Carlo samples. The corrected 95% upper bounds are: τ(15,30) < 0:018 (lowE, flat τ(15, 30), FlexKnot), (1) τ(15, 30) < 0:023 (lowE, flat knot, FlexKnot): (2) These bounds are a factor of 3 larger than the originally reported results. Consequently, the new bounds do not significantly improve upon previous results from Planck data presented in Millea & Bouchet (2018) as was stated, but are instead comparable. Equations (1) and (2) give results that are now similar to those of Heinrich & Hu (2021), who used the same Planck 2018 data to derive a 95% upper bound of 0.020 using the principal component analysis (PCA) model and uniform priors on the PCA mode amplitudes.

Canonical page: https://nerdi.pages.dev/paper/W3193094654
Read three real papers a day in Nerdi (iPhone): https://apps.apple.com/app/apple-store/id6813826387?pt=128757794&ct=web-paper&mt=8