TITLE:
CMBPol mission concept study: gravitational lensing.
AUTHOR(S):
Kendrick M. Smith, Asantha Cooray, Sudeep Das, Olivier Dore, Duncan Hanson, Chris Hirata, Manoj Kaplinghat, Brian Keating, Marilena LoVerde, Nathan
Miller, Graca Rocha, Meir Shimon, Oliver Zahn.
DATE:
2008 Nov 24 (arXiv, v1, posted).
AVAILABILITY:
arXiv 0811.3916 (free).
PUBLICATION INFORMATION:
N/A.
ABSTRACT:
Gravitational lensing of the cosmic microwave background by large-scale structure in the late universe is both a source of cosmological information and
a potential contaminant of primordial gravity waves. Because lensing imprints growth of structure in the late universe on the CMB, measurements of CMB
lensing will constrain parameters to which the CMB would not otherwise be sensitive, such as neutrino mass.
If the instrumental noise is sufficiently small (<~ 5 μK-arcmin), the gravitational lensing contribution to the large-scale B-mode will be the
limiting
source of contamination when constraining a stochastic background of gravity waves in the early universe, one of the most exciting prospects for future
CMB polarization experiments. High-sensitivity measurements of small-scale B-modes can reduce this contamination through a lens reconstruction
technique that separates the lensing and primordial contributions to the B-mode on large scales.
A fundamental design decision for a future CMB polarization experiment such as CMBpol is whether to have coarse angular resolution so that only the
large-scale B-mode (and the large-scale E-mode from reionization) is measured, or high resolution to additionally measure CMB lensing. The purpose of
this white paper is to evaluate the science case for CMB lensing in polarization: constraints on cosmological parameters, increased sensitivity to the
gravity wave B-mode via lens reconstruction, expected level of contamination from non-CMB foregrounds, and required control of beam systematics.
ADS BIBLIOGRAPHIC CODE: N/A.
COMMENTS: N/A.