CMB delensing for detecting primordial B-mode Signal

ORAL

Abstract

One of the major targets for next-generation CMB experiments is the detection of the primordial B-mode signal. Planning is under way for Stage-IV experiments that are projected to have instrumental noise small enough to make lensing and foregrounds the dominant source of uncertainty for estimating the tensor-to-scalar ratio $r$ from polarization maps. This makes delensing a crucial part of future CMB polarization science. In this paper we will present two likelihood methods for estimating the tensor-to-scalar ratio $r$ from CMB polarization observations. These two methods combine the benefits of a full scale likelihood approach with the tractability of the quadratic delensing technique. The first method probes high frequency primordial B-mode fluctuations via a pixel space local likelihood approximation. The second method is a pixel space, all order likelihood analysis of the low frequency (high signal-to-noise) quadratic delensed B-modes. The tractability of both methods relies on a crucial factorization of the pixel space covariance matrix of the polarization observations which allows one to compute the full likelihood profile, as a function of $r$, at the same computational cost of a single likelihood evaluation.

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Authors

  • Zhen Pan

    Univ of California, Davis

  • Ethan Anderes

    UC Davis, Lawrence Berkeley National Lab - ALS, National Institute of Standards and Technology - NCNR, Univ of California - Davis, University of California, Davis, California State University, Long Beach, University of California, Irvine, University of California, Merced, UC Merced, U Central Florida, Paul Scherrer Institute, Paul Scherrer Institute in Switzerland, Hartnell Comm Coll, University of Michigan, University of Nevada, Reno, National Security Technologies LLC, Livermore, California, Humboldt State University, Stanford University, San Diego State Univ, Institute of Mathematical Problems of Biology, Eindhoven University of Technology, University Of Nevada Reno, Univ of Nevada - Reno, University of Chicago, Physics Department of the University of Nevada, Reno, NV, USA, Institute for Academic Initiatives, PPC and Graduate School of Engineering, Osaka University, Joint Institute for High Temperatures, PPC and Graduate School of Engineering, Osaka University, Institute for Academic Initiatives, Joint Institute for High Temperatures, National Institute of Standards and Technology, Gaithersburg, MD, Department of Physics, UC Davis, Department of Physics & Astronomy, Univeristy of California Irvine, 92697, Department of Chemistry and of Physics, Univeristy of California Irvine, 92697, Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel 76100, Einstein Centre for Local-Realistic Physics, Cal State Long Beach, University of nevada, Reno, Nicolaus Copernicus University, Torun, Poland, University of Maryland, CERN, Univ of California, Davis

  • Ethan Anderes

    UC Davis, Lawrence Berkeley National Lab - ALS, National Institute of Standards and Technology - NCNR, Univ of California - Davis, University of California, Davis, California State University, Long Beach, University of California, Irvine, University of California, Merced, UC Merced, U Central Florida, Paul Scherrer Institute, Paul Scherrer Institute in Switzerland, Hartnell Comm Coll, University of Michigan, University of Nevada, Reno, National Security Technologies LLC, Livermore, California, Humboldt State University, Stanford University, San Diego State Univ, Institute of Mathematical Problems of Biology, Eindhoven University of Technology, University Of Nevada Reno, Univ of Nevada - Reno, University of Chicago, Physics Department of the University of Nevada, Reno, NV, USA, Institute for Academic Initiatives, PPC and Graduate School of Engineering, Osaka University, Joint Institute for High Temperatures, PPC and Graduate School of Engineering, Osaka University, Institute for Academic Initiatives, Joint Institute for High Temperatures, National Institute of Standards and Technology, Gaithersburg, MD, Department of Physics, UC Davis, Department of Physics & Astronomy, Univeristy of California Irvine, 92697, Department of Chemistry and of Physics, Univeristy of California Irvine, 92697, Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel 76100, Einstein Centre for Local-Realistic Physics, Cal State Long Beach, University of nevada, Reno, Nicolaus Copernicus University, Torun, Poland, University of Maryland, CERN, Univ of California, Davis