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Atacama Cosmology Telescope: Constraints on cosmic birefringence

Namikawa, Toshiya and Guan, Yilun and Darwish, Omar and Sherwin, Blake D. and Aiola, Simone and Battaglia, Nicholas and Beall, James A. and Becker, Daniel T. and Bond, J. Richard and Calabrese, Erminia and Chesmore, Grace E. and Choi, Steve K. and Devlin, Mark J. and Dunkley, Joanna and Dünner, Rolando and Fox, Anna E. and Gallardo, Patricio A. and Gluscevic, Vera and Han, Dongwon and Hasselfield, Matthew and Hilton, Gene C. and Hincks, Adam D. and Hložek, Renée and Hubmayr, Johannes and Huffenberger, Kevin and Hughes, John P. and Koopman, Brian J. and Kosowsky, Arthur and Louis, Thibaut and Lungu, Marius and MacInnis, Amanda and Madhavacheril, Mathew S. and Mallaby-Kay, Maya and Maurin, Loïc and McMahon, Jeffrey and Moodley, Kavilan and Naess, Sigurd and Nati, Federico and Newburgh, Laura B. and Nibarger, John P. and Niemack, Michael D. and Page, Lyman A. and Qu, Frank J. and Robertson, Naomi and Schillaci, Alessandro and Sehgal, Neelima and Sifón, Cristóbal and Simon, Sara M. and Spergel, David N. and Staggs, Suzanne T. and Storer, Emilie R. and van Engelen, Alexander and van Lanen, Jeff and Wollack, Edward J. (2020) Atacama Cosmology Telescope: Constraints on cosmic birefringence. Physical Review D, 101 (8). Art. No. 083527. ISSN 2470-0010.

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We present new constraints on anisotropic birefringence of the cosmic microwave background polarization using two seasons of data from the Atacama Cosmology Telescope covering 456 square degrees of sky. The birefringence power spectrum, measured using a curved-sky quadratic estimator, is consistent with zero. Our results provide the tightest current constraint on birefringence over a range of angular scales between 5 arc minutes and 9°. We improve previous upper limits on the amplitude of a scale-invariant birefringence power spectrum by a factor of between 2 and 3. Assuming a nearly massless axion field during inflation, our result is equivalent to a 2σ upper limit on the Chern-Simons coupling constant between axions and photons of g_(αγ) < 4.0×10⁻²/H_I, where HI is the inflationary Hubble scale.

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Additional Information:© 2020 American Physical Society. Received 1 February 2020; accepted 2 April 2020; published 17 April 2020. T. N. thanks Ryo Nagata and Levon Pogosian for helpful discussions. Some of the results in this paper have been derived using a dust simulation generated by Ref. [54] and public software of the healpy [81], HEALPix [82], and CAMB [83]. This work was supported by the U.S. National Science Foundation through Grants No. AST-1440226, No. AST0965625 and No. AST-0408698 for the ACT project, as well as Grants No. PHY-1214379 and No. PHY-0855887. Funding was also provided by Princeton University, the University of Pennsylvania, and a Canada Foundation for Innovation (CFI) grant to UBC. ACT operates in the Parque Astronomico Atacama in northern Chile under the auspices of the Comision Nacional de Investigacion Cientfica y Tecnologica de Chile (CONICYT). Computations were performed on the GPC and Niagara supercomputers at the SciNet HPC Consortium. SciNet is funded by the CFI under the auspices of Compute Canada, the Government of Ontario, the Ontario Research Fund Research Excellence, and the University of Toronto. The development of multichroic detectors and lenses was supported by NASA Grants No. NNX13AE56G and No. NNX14AB58G. Colleagues at AstroNorte and RadioSky provide logistical support and keep operations in Chile running smoothly. We also thank the Mishrahi Fund and the Wilkinson Fund for their generous support of the project. T. N., O. D., and B. D. S. acknowledge support from an Isaac Newton Trust Early Career Grant and from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation program (Grant Agreement No. 851274). B. D. S. further acknowledges support from an STFC Ernest Rutherford Fellowship. D. H., A. M., and N. S. acknowledge support from NSF Grant No. 1513618. J. D. and E. S. acknowledge support from NSF Grant No. 1814971. E. C. is supported by an STFC Ernest Rutherford Fellowship No. ST/M004856/2 and STFC Consolidated Grant No. ST/S00033X/1. L. M. received funding from CONICYT FONDECYT Grant No. 3170846. K. M. acknowledges support from the National Research Foundation of South Africa.
Funding AgencyGrant Number
Princeton UniversityUNSPECIFIED
University of PennsylvaniaUNSPECIFIED
Canada Foundation for InnovationUNSPECIFIED
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)UNSPECIFIED
Ontario Research Fund Research ExcellenceUNSPECIFIED
University of TorontoUNSPECIFIED
Isaac Newton TrustUNSPECIFIED
European Research Council (ERC)851274
Science and Technology Facilities Council (STFC)ST/M004856/2
Science and Technology Facilities Council (STFC)ST/S00033X/1
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)3170846
National Research Foundation (South Africa)UNSPECIFIED
Issue or Number:8
Record Number:CaltechAUTHORS:20200417-143354054
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:102639
Deposited By: Tony Diaz
Deposited On:17 Apr 2020 21:51
Last Modified:17 Apr 2020 21:51

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