A Caltech Library Service

Delensing CMB polarization with external datasets

Smith, Kendrick M. and Hanson, Duncan and LoVerde, Marilena and Hirata, Christopher M. and Zahn, Oliver (2012) Delensing CMB polarization with external datasets. Journal of Cosmology and Astroparticle Physics, 2012 (6). Art. No. 014. ISSN 1475-7516.

PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


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.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Hirata, Christopher M.0000-0002-2951-4932
Additional Information:© 2012 IOP Publishing Ltd and Sissa Medialab srl. Received November 8, 2011; Accepted May 15, 2012; Published June 8, 2012. This work was organized and initiated at the workshop "CMB Polarization workshop: theory and foregrounds" held at Fermilab from Jun 23-26 2008. We would like to thank the organizers and sta for a stimulating and productive atmosphere. A preliminary version of these results was included, with calculational details omitted, in the NASA Decadal Survey report [71]. KMS is supported by a Lyman Spitzer fellowship in the Department of Astrophysical Sciences at Princeton University. ML is supported as a Friends of the Institute for Advanced Study Member and by the NSF though AST-0807444. CH is supported by the U.S. Department of Energy (DE-FG03-92-ER40701), the National Science Foundation (AST-0807337), and the Alfred P. Sloan Foundation. OZ is supported by an Inaugural Fellowship by the Berkeley Center for Cosmological Physics. This research was partly funded by NASA Mission Concept Study award NNX08AT71G S01. We also acknowledge the organizational work of the Primordial Polarization Program Definition Team.
Funding AgencyGrant Number
Princeton UniversityUNSPECIFIED
Institute for Advanced StudyUNSPECIFIED
Department of Energy (DOE)DE-FG03-92-ER40701
Alfred P. Sloan FoundationUNSPECIFIED
Berkeley Center for Cosmological PhysicsUNSPECIFIED
Subject Keywords:gravitational waves and CMBR polarization; cosmological parameters from CMBR
Issue or Number:6
Classification Code:PACS: 98.70.Vc; 95.30.Sf; 98.62.Sb
Record Number:CaltechAUTHORS:20120813-115708355
Persistent URL:
Official Citation:Delensing CMB polarization with external datasets Kendrick M. Smith et al JCAP06(2012)014
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:33131
Deposited By: Aucoeur Ngo
Deposited On:13 Aug 2012 20:26
Last Modified:03 Oct 2019 04:07

Repository Staff Only: item control page