Planck 2018 results. VII. Isotropy and statistics of the CMB

Yashar Akrami (1) , M. Ashdown , J. Aumont , C. Baccigalupi , M. Ballardini , A. J. Banday (2) , R. B. Barreiro , N. Bartolo , S. Basak , K. Benabed (3) , M. Bersanelli (4) , P. Bielewicz , J. J. Bock (5, 6) , J. R. Bond (7) , J. Borrill (8) , F. R. Bouchet , F. Boulanger , M. Bucher (9) , C. Burigana , R. C. Butler , E. Calabrese , J.-F. Cardoso , B. Casaponsa , H. C. Chiang , L. P. L. Colombo , C. Combet (10) , D. Contreras , B. P. Crill , P. de Bernardis (11) , G. de Zotti , J. Delabrouille (9) , J.-M. Delouis (3) , E. Di Valentino , J. M. Diego , O. Doré (5) , M. Douspis , A. Ducout , X. Dupac , G. Efstathiou , F. Elsner (12) , T. A. Ensslin , H. K. Eriksen , Y. Fantaye , R. Fernandez-Cobos , F. Finelli , M. Frailis , A. A. Fraisse , E. Franceschi , A. Frolov (13) , S. Galeotta , S. Galli , K. Ganga (9) , R. T. Génova-Santos , M. Gerbino , T. Ghosh (14) , J. González-Nuevo , K. M. Górski (5) , A. Gruppuso , J. E. Gudmundsson , J. Hamann , W. Handley , F. K. Hansen , D. Herranz , E. Hivon (3) , Z. Huang , A. H. Jaffe , W. C. Jones , E. Keihänen , R. Keskitalo , K. Kiiveri , J. Kim , N. Krachmalnicoff , M. Kunz , H. Kurki-Suonio , G. Lagache (14) , J.-M. Lamarre (15) , A. Lasenby , M. Lattanzi , C. R. Lawrence , M. Le Jeune (9) , F. Levrier (15) , M. Liguori , P. B. Lilje , V. Lindholm , M. López-Caniego , Y.-Z. Ma , J. F. Macías-Pérez (10) , G. Maggio , D. Maino , N. Mandolesi , A. Mangilli (2) , A. Marcos-Caballero , M. Maris , P. G. Martin , E. Martínez-González , S. Matarrese (16) , N. Mauri , J. D. Mcewen , P. R. Meinhold , A. Mennella , M. Migliaccio , M.-A. Miville-Deschênes (17) , D. Molinari , A. Moneti (3) , L. Montier (2) , G. Morgante , A. Moss , P. Natoli , L. Pagano (14) , D. Paoletti , B. Partridge , F. Perrotta , V. Pettorino (18) , F. Piacentini , G. Polenta , J.-L. Puget (14) , J. P. Rachen , M. Reinecke , M. Remazeilles (19) , A. Renzi , G. Rocha (5) , C. Rosset (9) , G. Roudier (15, 9) , J. A. Rubiño-Martín , B. Ruiz-Granados , L. Salvati (14) , M. Savelainen , D. Scott (20) , E. P. S. Shellard , C. Sirignano , R. Sunyaev , A.-S. Suur-Uski , J. A. Tauber , D. Tavagnacco , M. Tenti , L. Toffolatti , M. Tomasi , T. Trombetti , L. Valenziano , J. Valiviita , B. van Tent (21) , P. Vielva , Francesca Villa , N. Vittorio , B. D. Wandelt (3) , I. K. Wehus , A. Zacchei , J. P. Zibin , A. Zonca

1 Astrophysique
2 IRAP - Institut de recherche en astrophysique et planétologie
3 IAP - Institut d'Astrophysique de Paris
4 UNIPR - Università degli studi di Parma = University of Parma
5 JPL - Jet Propulsion Laboratory
6 CALTECH - California Institute of Technology
7 CITA - Canadian Institute for Theoretical Astrophysics
8 LBNL - Lawrence Berkeley National Laboratory [Berkeley]
9 APC (UMR_7164) - AstroParticule et Cosmologie
10 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
11 Dipartimento di Fisica [Roma La Sapienza]
12 IAP - Institut d'Astrophysique de Paris
13 Laboratory for Phytosanitary Diagnostics and Forecasts, All-Russian Institute for Plant Protection
14 IAS - Institut d'astrophysique spatiale
15 LERMA (UMR_8112) - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique
16 Dipartimento di Fisica "G. Galilei"
17 CEA - Commissariat à l'énergie atomique et aux énergies alternatives
18 AIM (UMR_7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation
19 University of Manchester [Manchester]
20 UBC - University of British Columbia
21 IJCLab - Laboratoire de Physique des 2 Infinis Irène Joliot-Curie

Analysis of the Planck 2018 data set indicates that the statistical properties of the cosmic microwave background (CMB) temperature anisotropies are in excellent agreement with previous studies using the 2013 and 2015 data releases. In particular, they are consistent with the Gaussian predictions of the ΛCDM cosmological model, yet also confirm the presence of several so-called “anomalies” on large angular scales. The novelty of the current study, however, lies in being a first attempt at a comprehensive analysis of the statistics of the polarization signal over all angular scales, using either maps of the Stokes parameters, Q and U, or the E-mode signal derived from these using a new methodology (which we describe in an appendix). Although remarkable progress has been made in reducing the systematic effects that contaminated the 2015 polarization maps on large angular scales, it is still the case that residual systematics (and our ability to simulate them) can limit some tests of non-Gaussianity and isotropy. However, a detailed set of null tests applied to the maps indicates that these issues do not dominate the analysis on intermediate and large angular scales (i.e., ℓ ≲ 400). In this regime, no unambiguous detections of cosmological non-Gaussianity, or of anomalies corresponding to those seen in temperature, are claimed. Notably, the stacking of CMB polarization signals centred on the positions of temperature hot and cold spots exhibits excellent agreement with the ΛCDM cosmological model, and also gives a clear indication of how Planck provides state-of-the-art measurements of CMB temperature and polarization on degree scales.

Keywords: cosmology: observations; cosmic background radiation; polarization; methods: data analysis; methods: statistical

Domains: Physics [physics]; Astrophysics [astro-ph]

Yashar Akrami, M. Ashdown, J. Aumont, C. Baccigalupi, M. Ballardini, et al.. Planck 2018 results. VII. Isotropy and statistics of the CMB. Astronomy and Astrophysics - A&A, 2020, 641, pp.A7. ⟨10.1051/0004-6361/201935201⟩. ⟨cea-02936949⟩