Delensing CMB polarization with external datasets
Abstract
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.
- Publication:
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Journal of Cosmology and Astroparticle Physics
- Pub Date:
- June 2012
- DOI:
- 10.1088/1475-7516/2012/06/014
- arXiv:
- arXiv:1010.0048
- Bibcode:
- 2012JCAP...06..014S
- Keywords:
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- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- typos corrected