The Atacama Cosmology Telescope: Delensed power spectra and parameters

ACT collaboration

doi:10.1088/1475-7516/2021/01/031

The Atacama Cosmology Telescope: Delensed power spectra and parameters

ACT collaboration

Physics and Astronomy

Stony Brook University
Simons Foundation
Arizona State University
University of Cambridge
Perimeter Institute for Theoretical Physics
Princeton University
Cornell University
National Institute of Standards and Technology
Cardiff University
University of Pennsylvania
University of California at Berkeley
Lawrence Berkeley National Laboratory
Pennsylvania State University
Columbia University
University of KwaZulu-Natal
University of Toronto
Rutgers - The State University of New Jersey, New Brunswick
University of Pittsburgh
IN2P3/CNRS
University of Milan - Bicocca
Haverford College
California Institute of Technology
NASA Goddard Space Flight Center

Research output: Contribution to journal › Article › peer-review

22 Scopus citations

Abstract

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.

Original language	English
Article number	031
Journal	Journal of Cosmology and Astroparticle Physics
Volume	2021
Issue number	1
DOIs	https://doi.org/10.1088/1475-7516/2021/01/031
State	Published - Jan 2021

Keywords

Cosmological parameters from CMBR
Weak gravitational lensing

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10.1088/1475-7516/2021/01/031

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@article{b9f7dbf3aee346969159e26170368824,

title = "The Atacama Cosmology Telescope: Delensed power spectra and parameters",

abstract = "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.",

keywords = "Cosmological parameters from CMBR, Weak gravitational lensing",

author = "\{ACT collaboration\} and Dongwon Han and Neelima Sehgal and Amanda MacInnis and \{van Engelen\}, Alexander and Sherwin, \{Blake D.\} and Madhavacheril, \{Mathew S.\} and Simone Aiola and Nicholas Battaglia and Beall, \{James A.\} and Becker, \{Daniel T.\} and Erminia Calabrese and Choi, \{Steve K.\} and Omar Darwish and Denison, \{Edward V.\} and Devlin, \{Mark J.\} and Jo Dunkley and Simone Ferraro and Fox, \{Anna E.\} and Matthew Hasselfield and \{Colin Hill\}, J. and Hilton, \{Gene C.\} and Matt Hilton and Ren{\'e}e Hlo{\v z}ek and Johannes Hubmayr and Hughes, \{John P.\} and Arthur Kosowsky and \{van Lanen\}, Jeff and Thibaut Louis and Kavilan Moodley and Sigurd Naess and Toshiya Namikawa and Federico Nati and Nibarger, \{John P.\} and Niemack, \{Michael D.\} and Page, \{Lyman A.\} and Bruce Partridge and Qu, \{Frank J.\} and Alessandro Schillaci and Spergel, \{David N.\} and Suzanne Staggs and Emilie Storer and Wollack, \{Edward J.\}",

note = "Publisher Copyright: {\textcopyright} 2021 IOP Publishing Ltd and Sissa Medialab",

year = "2021",

month = jan,

doi = "10.1088/1475-7516/2021/01/031",

language = "English",

volume = "2021",

journal = "Journal of Cosmology and Astroparticle Physics",

issn = "1475-7516",

number = "1",

}

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.

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 - https://www.scopus.com/pages/publications/85100380110

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 -

The Atacama Cosmology Telescope: Delensed power spectra and parameters

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Keywords

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