[1112.0567] Lensing of 21-cm Fluctuations by Primordial Gravitational Waves

Authors: Laura Book, Marc Kamionkowski, Fabian Schmidt

Date: 2 Dec 2011

Abstract: Weak-gravitational-lensing distortions to the intensity pattern of 21-cm radiation from the dark ages can be decomposed geometrically into curl and curl-free components. Lensing by primordial gravitational waves induces a curl component, while the contribution from lensing by density fluctuations is strongly suppressed. Angular fluctuations in the 21-cm background extend to very small angular scales, and measurements at different frequencies probe different shells in redshift space. There is thus a huge trove of information with which to reconstruct the curl component of the lensing field, allowing tensor-to-scalar ratios conceivably as small as r ~ 10ˆ{-9} - far smaller than those currently accessible - to be probed.

abs pdf

Dec 07, 2011

1112.0567 (/preprints)
2011-12-07, 17:58 [edit]


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