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Title: Delensing CMB polarization with external datasets

Journal Article · · Journal of Cosmology and Astroparticle Physics
 [1];  [2];  [3];  [4];  [5]
  1. Princeton University Observatory, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States)
  2. Institute of Astronomy and Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)
  3. Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)
  4. California Institute of Technology, Mail Code 350-17, Pasadena, CA 91125 (United States)
  5. Berkeley Center for Cosmological Physics, University of California, 366 LeConte Hall, Berkeley, CA 94720 (United States)

One of the primary scientific targets of current and future CMB polarization experiments is the search for a stochastic background of gravity waves in the early universe. As instrumental sensitivity improves, the limiting factor will eventually be B-mode power generated by gravitational lensing, which can be removed through use of so-called ''delensing'' algorithms. We forecast prospects for delensing using lensing maps which are obtained externally to CMB polarization: either from large-scale structure observations, or from high-resolution maps of CMB temperature. We conclude that the forecasts in either case are not encouraging, and that significantly delensing large-scale CMB polarization requires high-resolution polarization maps with sufficient sensitivity to measure the lensing B-mode. We also present a simple formalism for including delensing in CMB forecasts which is computationally fast and agrees well with Monte Carlos.

OSTI ID:
22280003
Journal Information:
Journal of Cosmology and Astroparticle Physics, Vol. 2012, Issue 06; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
Country of Publication:
United States
Language:
English