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A demonstration of improved constraints on primordial gravitational waves with delensing

Ade, P. A. R. and Ahmed, Z. and Amiri, M. and Anderson, A. J. and Austermann, J. E. and Avva, J. S. and Barkats, D. and Basu Thakur, R. and Beall, J. A. and Bender, A. N. and Benson, B. A. and Bianchini, F. and Bischoff, C. A. and Bleem, L. E. and Bock, J. J. and Boenish, H. and Bullock, E. and Buza, V. and Carlstrom, J. E. and Chang, C. L. and Cheshire, J. R. and Chiang, H. C. and Chou, T-L. and Citron, R. and Connors, J. and Moran, C. Corbett and Cornelison, J. and Crawford, T. M. and Crites, A. T. and Crumrine, M. and Cukierman, A. and de Haan, T. and Dierickx, M. and Dobbs, M. A. and Duband, L. and Everett, W. and Fatigoni, S. and Filippini, J. P. and Fliescher, S. and Gallicchio, J. and George, E. M. and St. Germaine, T. and Goeckner-Wald, N. and Goldfinger, D. C. and Grayson, J. and Gupta, N. and Hall, G. and Halpern, M. and Halverson, N. W. and Harrison, S. and Henderson, S. and Henning, J. W. and Hildebrandt, S. R. and Hilton, G. C. and Holder, G. P. and Holzapfel, W. L. and Hrubes, J. D. and Huang, N. and Hubmayr, J. and Hui, H. and Irwin, K. D. and Kang, J. and Karkare, K. S. and Karpel, E. and Kefeli, S. and Kernasovskiy, S. A. and Knox, L. and Kovac, J. M. and Kuo, C. L. and Lau, K. and Lee, A. T. and Leitch, E. M. and Li, D. and Lowitz, A. and Manzotti, A. and McMahon, J. J. and Megerian, K. and Meyer, S. S. and Millea, M. and Mocanu, L. M. and Moncelsi, L. and Montgomery, J. and Nadolski, A. and Namikawa, T. and Natoli, T. and Netterfield, C. B. and Nguyen, H. T. and Nibarger, J. P. and Noble, G. and Novosad, V. and O’Brient, R. and Ogburn, R. W. and Omori, Y. and Padin, S. and Palladino, S. and Patil, S. and Prouve, T. and Pryke, C. and Racine, B. and Reichardt, C. L. and Reintsema, C. D. and Richter, S. and Ruhl, J. E. and Saliwanchik, B. R. and Schaffer, K. K. and Schillaci, A. and Schmitt, B. L. and Schwarz, R. and Sheehy, C. D. and Sievers, C. and Smecher, G. and Soliman, A. and Stark, A. A. and Steinbach, B. and Sudiwala, R. V. and Teply, G. P. and Thompson, K. L. and Tolan, J. E. and Tucker, C. and Turner, A. D. and Umiltà, C. and Veach, T. and Vieira, J. D. and Vieregg, A. G. and Wandui, A. and Wang, G. and Weber, A. C. and Whitehorn, N. and Wiebe, D. V. and Willmert, J. and Wong, C. L. and Wu, W. L. K. and Yang, H. and Yefremenko, V. and Yoon, K. W. and Young, E. and Yu, C. and Zeng, L. and Zhang, C. (2021) A demonstration of improved constraints on primordial gravitational waves with delensing. Physical Review D, 103 (2). Art. No. 022004. ISSN 2470-0010.

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We present a constraint on the tensor-to-scalar ratio, r, derived from measurements of cosmic microwave background (CMB) polarization B-modes with “delensing,” whereby the uncertainty on r contributed by the sample variance of the gravitational lensing B-modes is reduced by cross-correlating against a lensing B-mode template. This template is constructed by combining an estimate of the polarized CMB with a tracer of the projected large-scale structure. The large-scale-structure tracer used is a map of the cosmic infrared background derived from Planck satellite data, while the polarized CMB map comes from a combination of South Pole Telescope, BICEP/Keck, and Planck data. We expand the BICEP/Keck likelihood analysis framework to accept a lensing template and apply it to the BICEP/Keck dataset collected through 2014 using the same parametric foreground modeling as in the previous analysis. From simulations, we find that the uncertainty on r is reduced by ∼10%, from σ(r) = 0.024 to 0.022, which can be compared with a ∼26% reduction obtained when using a perfect lensing template or if there were zero lensing B-modes. Applying the technique to the real data, the constraint on r is improved from r_(0.05) < 0.090 to r_(0.05) < 0.082 (95% C.L.). This is the first demonstration of improvement in an r constraint through delensing.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Ade, P. A. R.0000-0002-5127-0401
Basu Thakur, R.0000-0002-3351-3078
Bianchini, F.0000-0003-4847-3483
Bock, J. J.0000-0002-5710-5212
Connors, J.0000-0002-6094-2943
Moran, C. Corbett0000-0003-2088-7465
Cukierman, A.0000-0002-7471-719X
de Haan, T.0000-0001-5105-9473
Dierickx, M.0000-0002-3519-8593
Filippini, J. P.0000-0001-8217-6832
Halpern, M.0000-0002-1760-0868
Hildebrandt, S. R.0000-0003-0220-0009
Hilton, G. C.0000-0003-4247-467X
Karkare, K. S.0000-0002-5215-6993
Manzotti, A.0000-0003-0057-877X
Moncelsi, L.0000-0002-4242-3015
Omori, Y.0000-0002-0963-7310
Schillaci, A.0000-0002-0512-1042
Tucker, C.0000-0002-1851-3918
Wandui, A.0000-0002-8232-7343
Whitehorn, N.0000-0002-3157-0407
Wu, W. L. K.0000-0001-5411-6920
Zhang, C.0000-0001-8288-5823
Additional Information:© 2021 American Physical Society. Received 18 November 2020; accepted 23 December 2020; published 26 January 2021. The authors thank Dominic Beck and Chang Feng for useful comments on an early version of the draft. The bicep2/Keck Array projects have been made possible through a series of grants from the National Science Foundation including Grants No. 0742818, No. 0742592, No. 1044978, No. 1110087, No. 1145172, No. 1145143, No. 1145248, No. 1639040, No. 1638957, No. 1638978, and No. 1638970, and by the Keck Foundation. The development of antenna-coupled detector technology was supported by the JPL Research and Technology Development Fund, and by NASA Grants No. 06-ARPA206-0040, No. 10-SAT10-0017, No. 12-SAT12-0031, No. 14-SAT14-0009, and No. 16-SAT-16-0002. The development and testing of focal planes were supported by the Gordon and Betty Moore Foundation at Caltech. Readout electronics were supported by a Canada Foundation for Innovation grant to UBC. Support for quasioptical filtering was provided by UK STFC Grant No. ST/N000706/1. Some of the computations in this paper were run on the Odyssey cluster supported by the FAS Science Division Research Computing Group at Harvard University. The analysis effort at Stanford and S. L. A. C. is partially supported by the U.S. DOE Office of Science. We thank the staff of the U.S. Antarctic Program and in particular the South Pole Station without whose help this research would not have been possible. Most special thanks go to our heroic winter-overs Robert Schwarz and Steffen Richter. We thank all those who have contributed past efforts to the bicep–Keck Array series of experiments, including the bicep1 team. S. P. T. is supported by the National Science Foundation through Grants No. PLR-1248097 and No. OPP-1852617. Partial support is also provided by the NSF Physics Frontier Center Grant No. PHY-1125897 to the Kavli Institute of Cosmological Physics at the University of Chicago, the Kavli Foundation and the Gordon and Betty Moore Foundation Grant No. GBMF 947. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The Melbourne group acknowledges support from the University of Melbourne and an Australian Research Council’s Future Fellowship (FT150100074). Work at Argonne National Lab is supported by UChicago Argonne LLC, Operator of Argonne National Laboratory (Argonne). Argonne, a U.S. Department of Energy Office of Science Laboratory, is operated under Contract No. DE-AC02-06CH11357. We also acknowledge support from the Argonne Center for Nanoscale Materials. Work at McGill is supported by the Natural Science and Engineering Research Council of Canada, the Canadian Institute for Advanced Research, and M. D. acknowledges a Killam research fellowship W. L. K. W. is supported in part by the Kavli Institute for Cosmological Physics at the University of Chicago through Grant No. NSF PHY-1125897, an endowment from the Kavli Foundation and its founder Fred Kavli, and by the Department of Energy, Laboratory Directed Research and Development program and as part of the Panofsky Fellowship program at SLAC National Accelerator Laboratory, under Contract No. DE-AC02-76SF00515. B. B. is supported by the Fermi Research Alliance LLC under Contract No. De-AC02- 07CH11359 with the U.S. Department of Energy. We acknowledge the use of many python packages: ipython [69], matplotlib [70], scipy [71], and healpy [72,73]. We also thank the Planck and WMAP teams for the use of their data. Some of the sky simulations used in this paper were developed by the WebSky Extragalactic CMB Mocks team, with the continuous support of the Canadian Institute for Theoretical Astrophysics (CITA), the Canadian Institute for Advanced Research (CIFAR), and the Natural Sciences and Engineering Research Council of Canada (NSERC), and were generated on the Niagara supercomputer at the SciNet HPC Consortium. SciNet is funded by: the Canada Foundation for Innovation under the auspices of Compute Canada; the Government of Ontario; Ontario Research Fund—Research Excellence; and the University of Toronto.
Group:Astronomy Department
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
JPL Research and Technology Development FundUNSPECIFIED
Gordon and Betty Moore FoundationGBMF 947
Canada Foundation for InnovationUNSPECIFIED
Science and Technology Facilities Council (STFC)ST/N000706/1
Harvard UniversityUNSPECIFIED
Department of Energy (DOE)DE-AC02-05CH11231
Kavli FoundationUNSPECIFIED
University of MelbourneUNSPECIFIED
Australian Research CouncilFT150100074
Department of Energy (DOE)DE-AC02-06CH11357
Argonne Center for Nanoscale MaterialsUNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Canadian Institute for Advanced Research (CIFAR)UNSPECIFIED
Killam Research FellowshipUNSPECIFIED
Kavli Institute for Cosmological PhysicsUNSPECIFIED
Department of Energy (DOE)DE-AC02-76SF00515
Department of Energy (DOE)DE-AC02-07CH11359
Canadian Institute for Theoretical Astrophysics (CITA)UNSPECIFIED
Government of OntarioUNSPECIFIED
Ontario Research Fund-Research ExcellenceUNSPECIFIED
University of TorontoUNSPECIFIED
Canadian Institute for Advanced Research (CIFAR)UNSPECIFIED
Canada Foundation for InnovationUNSPECIFIED
Issue or Number:2
Record Number:CaltechAUTHORS:20210127-093358968
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:107771
Deposited By: Tony Diaz
Deposited On:28 Jan 2021 00:16
Last Modified:28 Jan 2021 00:16

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