Can weak lensing surveys confirm BICEP2 ?
Abstract
The detection of B-modes in the Cosmic Microwave Background (CMB) polarization by the BICEP2 experiment, if interpreted as evidence for a primordial gravitational wave background, has enormous ramifications for cosmology and physics. It is crucial to test this hypothesis with independent measurements. A gravitational wave background leads to B-modes in galaxy shape correlations (shear) both through lensing and tidal alignment effects. Since the systematics and foregrounds of galaxy shapes and CMB polarization are entirely different, a detection of a cross-correlation between the two observables would provide conclusive proof for the existence of a primordial gravitational wave background. We find that upcoming weak lensing surveys will be able to detect the cross-correlation between B-modes of the CMB and galaxy shapes. However, this detection is not sufficient to confirm or falsify the hypothesis of a primordial origin for CMB B-mode polarization.
Keywords
Cite
@article{arxiv.1406.4871,
title = {Can weak lensing surveys confirm BICEP2 ?},
author = {Nora Elisa Chisari and Cora Dvorkin and Fabian Schmidt},
journal= {arXiv preprint arXiv:1406.4871},
year = {2016}
}
Comments
7 pages, 3 figures, published in PRD