TY - JOUR
T1 - The Atacama Cosmology Telescope
T2 - Delensed power spectra and parameters
AU - ACT collaboration
AU - Han, Dongwon
AU - Sehgal, Neelima
AU - MacInnis, Amanda
AU - van Engelen, Alexander
AU - Sherwin, Blake D.
AU - Madhavacheril, Mathew S.
AU - Aiola, Simone
AU - Battaglia, Nicholas
AU - Beall, James A.
AU - Becker, Daniel T.
AU - Calabrese, Erminia
AU - Choi, Steve K.
AU - Darwish, Omar
AU - Denison, Edward V.
AU - Devlin, Mark J.
AU - Dunkley, Jo
AU - Ferraro, Simone
AU - Fox, Anna E.
AU - Hasselfield, Matthew
AU - Colin Hill, J.
AU - Hilton, Gene C.
AU - Hilton, Matt
AU - Hložek, Renée
AU - Hubmayr, Johannes
AU - Hughes, John P.
AU - Kosowsky, Arthur
AU - van Lanen, Jeff
AU - Louis, Thibaut
AU - Moodley, Kavilan
AU - Naess, Sigurd
AU - Namikawa, Toshiya
AU - Nati, Federico
AU - Nibarger, John P.
AU - Niemack, Michael D.
AU - Page, Lyman A.
AU - Partridge, Bruce
AU - Qu, Frank J.
AU - Schillaci, Alessandro
AU - Spergel, David N.
AU - Staggs, Suzanne
AU - Storer, Emilie
AU - Wollack, Edward J.
N1 - Publisher Copyright:
© 2021 IOP Publishing Ltd and Sissa Medialab
PY - 2021/1
Y1 - 2021/1
N2 - We present ΛCDM cosmological parameter constraints obtained from delensed microwave background power spectra. Lensing maps from a subset of DR4 data from the Atacama Cosmology Telescope (ACT) are used to undo the lensing effect in ACT spectra observed at 150 and 98 GHz. At 150 GHz, we remove the lensing distortion with an effective efficiency of 30% (TT), 30% (EE), 26% (TE) and 20% (BB); this results in detections of the delensing effect at 8.7σ (TT), 5.1σ (EE), 2.6σ (TE), and 2.4σ (BB) significance. The combination of 150 and 98 GHz TT, EE, and TE delensed spectra is well fit by a standard ΛCDM model. We also measure the shift in best-fit parameters when fitting delensed versus lensed spectra; while this shift does not inform our ability to measure cosmological parameters, it does provide a three-way consistency check among the lensing inferred from the best-fit parameters, the lensing in the CMB power spectrum, and the reconstructed lensing map. This shift is predicted to be zero when fitting with the correct model since both lensed and delensed spectra originate from the same region of sky. Fitting with a ΛCDM model and marginalizing over foregrounds, we find that the shift in cosmological parameters is consistent with zero. Our results show that gravitational lensing of the microwave background is internally consistent within the framework of the standard cosmological model.
AB - We present ΛCDM cosmological parameter constraints obtained from delensed microwave background power spectra. Lensing maps from a subset of DR4 data from the Atacama Cosmology Telescope (ACT) are used to undo the lensing effect in ACT spectra observed at 150 and 98 GHz. At 150 GHz, we remove the lensing distortion with an effective efficiency of 30% (TT), 30% (EE), 26% (TE) and 20% (BB); this results in detections of the delensing effect at 8.7σ (TT), 5.1σ (EE), 2.6σ (TE), and 2.4σ (BB) significance. The combination of 150 and 98 GHz TT, EE, and TE delensed spectra is well fit by a standard ΛCDM model. We also measure the shift in best-fit parameters when fitting delensed versus lensed spectra; while this shift does not inform our ability to measure cosmological parameters, it does provide a three-way consistency check among the lensing inferred from the best-fit parameters, the lensing in the CMB power spectrum, and the reconstructed lensing map. This shift is predicted to be zero when fitting with the correct model since both lensed and delensed spectra originate from the same region of sky. Fitting with a ΛCDM model and marginalizing over foregrounds, we find that the shift in cosmological parameters is consistent with zero. Our results show that gravitational lensing of the microwave background is internally consistent within the framework of the standard cosmological model.
KW - Cosmological parameters from CMBR
KW - Weak gravitational lensing
UR - http://www.scopus.com/inward/record.url?scp=85100380110&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85100380110&partnerID=8YFLogxK
U2 - 10.1088/1475-7516/2021/01/031
DO - 10.1088/1475-7516/2021/01/031
M3 - Article
AN - SCOPUS:85100380110
SN - 1475-7516
VL - 2021
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
IS - 1
M1 - 031
ER -