Tuesday, January 24, 2012

1201.4527 (Yu Yu et al.)

Gaussianizing the non-Gaussian lensing convergence field II: the applicability to noisy data    [PDF]

Yu Yu, Pengjie Zhang, Weipeng Lin, Weiguang Cui, James N. Fry
In paper I (Yu et al. 2011 [1]), we show through N-body simulation that a local monotonic Gaussian transformation can significantly reduce non-Gaussianity in noise-free lensing convergence field. This makes the Gaussianization a promising theoretical tool to understand high-order lensing statistics. Here we present a study of its applicability in lensing data analysis, in particular when shape measurement noise is presented in lensing convergence maps. (1) We find that shape measure- ment noise significantly degrades the Gaussianization performance and the degradation increases for shallower surveys. (2) Wiener filter is efficient to reduce the impact of shape measurement noise. The Gaussianization of the Wiener filtered lensing maps is able to suppress skewness, kurtosis, 5th- and 6th-order cumulants by a factor of 10 or more. It also works efficiently to reduce the bispectrum well to zero.
View original: http://arxiv.org/abs/1201.4527

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