1303.4626 (Toyokazu Sekiguchi et al.)

Optimal constraint on g_NL from CMB    [PDF]

Toyokazu Sekiguchi, Naoshi Sugiyama

An optimal method to constrain the non-linearity parameter g_NL of the local-type non-Gaussianity from CMB data is proposed. The optimal estimator of g_NL is computed in the real space, which significantly reduces the computational cost and enables us to apply the method to the actual data. This method provides a much tighter constraint on g_NL than any other suboptimal methods. Applying our method to the WMAP 9-year data, for example, 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.

View original: http://arxiv.org/abs/1303.4626