Exploring cosmic origins with CORE: Gravitational lensing of the CMB

Anthony Challinor , Rupert Allison , Julien Carron , Josquin Errard (1, 2, 3) , Stephen Feeney , Thomas Kitching , Julien Lesgourgues , Antony Lewis , Íñigo Zubeldía , Ana Achucarro , Peter Ade , Mark Ashdown , Mario Ballardini , A.J. Banday (4) , Ranajoy Banerji (3) , James Bartlett (3) , Nicola Bartolo , Soumen Basak , Daniel Baumann , Marco Bersanelli , Anna Bonaldi , Matteo Bonato , Julian Borrill , François Bouchet (5) , François Boulanger (6) , Thejs Brinckmann , Martin Bucher (3) , Carlo Burigana , Alessandro Buzzelli , Zhen-Yi Cai , Martino Calvo (7) , Carla-Sofia Carvalho , Gabriella Castellano , Jens Chluba , Sebastien Clesse , Ivan Colantoni , Alessandro Coppolecchia , Martin Crook , Giuseppe d'Alessandro , Paolo de Bernardis , Giancarlo de Gasperis , Gianfranco de Zotti , Jacques Delabrouille (3) , Eleonora Di Valentino (5, 2) , Jose-Maria Diego , Raul Fernandez-Cobos , Simone Ferraro , Fabio Finelli , Francesco Forastieri , Silvia Galli (5) , Ricardo Genova-Santos , Martina Gerbino , Joaquin González-Nuevo , Sebastian Grandis , Joshua Greenslade , Steffen Hagstotz , Shaul Hanany , Will Handley , Carlos Hernandez-Monteagudo , Carlos Hervías-Caimapo , Matthew Hills , Eric Hivon , Kimmo Kiiveri , Ted Kisner , Martin Kunz , Hannu Kurki-Suonio , Luca Lamagna , Anthony Lasenby , Massimiliano Lattanzi , Michele Liguori , Valtteri Lindholm , Marcos López-Caniego , Gemma Luzzi , Bruno Maffei (6) , Enrique Martinez-González , C.J.A.P. Martins , Silvia Masi , Darragh Mccarthy , Alessandro Melchiorri , Jean-Baptiste Melin (8) , Diego Molinari , Alessandro Monfardini (9) , Paolo Natoli , Mattia Negrello , Alessio Notari , Alessandro Paiella , Daniela Paoletti , Guillaume Patanchon (3) , Michel Piat (3) , Giampaolo Pisano , Linda Polastri , Gianluca Polenta , Agnieszka Pollo , Vivian Poulin (10) , Miguel Quartin , Mathieu Remazeilles , Matthieu Roman (1) , Jose-Alberto Rubino-Martin , Laura Salvati , Andrea Tartari (3) , Maurizio Tomasi , Denis Tramonte , Neil Trappe , Tiziana Trombetti , Carole Tucker , Jussi Valiviita , Rien van de Weijgaert , Bartjan van Tent (11) , Vincent Vennin (3) , Patricio Vielva , Nicola Vittorio , Karl Young , Mario Zannoni

1 LPNHE (UMR_7585) - Laboratoire de Physique Nucléaire et de Hautes Énergies
2 Institut Lagrange de Paris
3 APC (UMR_7164) - AstroParticule et Cosmologie
4 IRAP - Institut de recherche en astrophysique et planétologie
5 IAP - Institut d'Astrophysique de Paris
6 IAS - Institut d'astrophysique spatiale
7 NEEL - Cryo - Cryogénie
8 DPhP - Département de Physique des Particules (ex SPP)
9 NEEL - HELFA - Hélium : du fondamental aux applications
10 LAPTH - Laboratoire d'Annecy-le-Vieux de Physique Théorique
11 LPT - Laboratoire de Physique Théorique d'Orsay [Orsay]

Lensing of the cosmic microwave background (CMB) is now a well-developed probe of the clustering of the large-scale mass distribution over a broad range of redshifts. By exploiting the non-Gaussian imprints of lensing in the polarization of the CMB, the CORE mission will allow production of a clean map of the lensing deflections over nearly the full-sky. The number of high-S/N modes in this map will exceed current CMB lensing maps by a factor of 40, and the measurement will be sample-variance limited on all scales where linear theory is valid. Here, we summarise this mission product and discuss the science that will follow from its power spectrum and the cross-correlation with other clustering data. For example, the summed mass of neutrinos will be determined to an accuracy of 17 meV combining CORE lensing and CMB two-point information with contemporaneous measurements of the baryon acoustic oscillation feature in the clustering of galaxies, three times smaller than the minimum total mass allowed by neutrino oscillation measurements. Lensing has applications across many other science goals of CORE, including the search for B-mode polarization from primordial gravitational waves. Here, lens-induced B-modes will dominate over instrument noise, limiting constraints on the power spectrum amplitude of primordial gravitational waves. With lensing reconstructed by CORE, one can "delens" the observed polarization internally, reducing the lensing B-mode power by 60 %. This can be improved to 70 % by combining lensing and measurements of the cosmic infrared background from CORE, leading to an improvement of a factor of 2.5 in the error on the amplitude of primordial gravitational waves compared to no delensing (in the null hypothesis of no primordial B-modes). Lensing measurements from CORE will allow calibration of the halo masses of the tens of thousands of galaxy clusters that it will find, with constraints dominated by the clean polarization-based estimators. The 19 frequency channels proposed for CORE will allow accurate removal of Galactic emission from CMB maps. We present initial findings that show that residual Galactic foreground contamination will not be a significant source of bias for lensing power spectrum measurements with CORE.

Mots clés: B-mode: lens; gravitation: lens; cosmic background radiation: polarization; gravitational radiation: power spectrum; gravitational radiation: primordial; galaxy: cluster; neutrino: mass; halo: mass; neutrino: oscillation; non-Gaussianity; calibration; deflection; estimator; redshift; noise

Domaines: Astrophysique [astro-ph]

Anthony Challinor, Rupert Allison, Julien Carron, Josquin Errard, Stephen Feeney, et al.. Exploring cosmic origins with CORE: Gravitational lensing of the CMB. Journal of Cosmology and Astroparticle Physics, 2018, 04, pp.018. ⟨10.1088/1475-7516/2018/04/018⟩. ⟨hal-01763818⟩