Optimal constraint on g_NL from CMB
Abstract
An optimal method to constrain the non-linearity parameter g_NL of the local-type non-Gaussianity from CMB data is proposed. Our optimal estimator for g_NL is separable and can be efficiently computed in real space. Combining the exact filtering of CMB maps with the full covariance matrix, our method allows us to extract cosmological information from observed data as much as possible and obtain a tighter constraint on g_NL than previous studies. Applying our method to the WMAP 9-year data, we obtain the constraint g_NL = (-3.3 +- 2.2) 10^5, which is a few times tighter than previous ones. We also make a forecast for PLANCK data by using the Fisher matrix analysis.
Keywords
Cite
@article{arxiv.1303.4626,
title = {Optimal constraint on g_NL from CMB},
author = {Toyokazu Sekiguchi and Naoshi Sugiyama},
journal= {arXiv preprint arXiv:1303.4626},
year = {2013}
}
Comments
13 pages, 2 tables; Several tests are performed to validate the results; accepted for publication in JCAP