An Estimate of the Primordial Non-Gaussianity Parameter f_NL Using the Needlet Bispectrum from WMAP
Cosmology and Nongalactic Astrophysics
2009-08-11 v2
Abstract
We use the full bispectrum of spherical needlets applied to the WMAP data of the cosmic microwave background as an estimator for the primordial non-Gaussianity parameter f_NL. We use needlet scales up to l_max=1000 and the KQ75 galactic cut and find f_NL=84 +/- 40 corrected for point source bias. We also introduce a set of consistency tests to validate our results against the possible influence of foreground residuals or systematic errors. In particular, fluctuations in the value of f_NL obtained from different frequency channels, different masks and different multipoles are tested against simulated maps. All variations in f_NL estimates are found statistically consistent with simulations.
Cite
@article{arxiv.0901.3154,
title = {An Estimate of the Primordial Non-Gaussianity Parameter f_NL Using the Needlet Bispectrum from WMAP},
author = {Oystein Rudjord and Frode K. Hansen and Xiaohong Lan and Michele Liguori and Domenico Marinucci and Sabino Matarrese},
journal= {arXiv preprint arXiv:0901.3154},
year = {2009}
}
Comments
9 pages, 2 figures