Internal Delensing of Cosmic Microwave Background Polarization <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math>-Modes with the POLARBEAR Experiment
S. Adachi, M. A. O. Aguilar Faúndez, Y. Akiba, Aamir Ali, Kam Arnold, C. Baccigalupi, Darcy Barron, D. Beck, F. Bianchini, J. Borrill, Julien Carron, K. Cheung, Y. Chinone, Kevin T. Crowley, H. El Bouhargani, T. Elleflot, Josquin Errard, Giulio Fabbian, Chang Feng, T. Fujino, N. Goeckner-Wald, M. Hasegawa, M. Hazumi, Charles A. Hill, L. Howe, N. Katayama, Brian Keating, S. Kikuchi, A. Kusaka, A. T. Lee, D. Leon, Eric V. Linder, L. N. Lowry, Frederick Matsuda, T. Matsumura, Y. Minami, Toshiya Namikawa, M. Navaroli, H. Nishino, J. Peloton, A. T. P. Pham, D. Poletti, Giuseppe Puglisi, C. L. Reichardt, Y. Segawa, B. D. Sherwin, Maximiliano Silva-Feaver, P. Siritanasak, R. Stompor, O. Tajima, S. Takatori, D. Tanabe, G. P. Teply, C. Vergès
Abstract
Using only cosmic microwave background polarization data from the polarbear experiment, we measure B-mode polarization delensing on subdegree scales at more than 5σ significance. We achieve a 14% B-mode power variance reduction, the highest to date for internal delensing, and improve this result to 22% by applying for the first time an iterative maximum a posteriori delensing method. Our analysis demonstrates the capability of internal delensing as a means of improving constraints on inflationary models, paving the way for the optimal analysis of next-generation primordial B-mode experiments.