Journal Article

The effect of the linear term on the wavelet estimator of primordial non-Gaussianity

A. Curto, E. Martínez-González and R. B. Barreiro

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 426, issue 2, pages 1361-1368
Published in print October 2012 | ISSN: 0035-8711
Published online October 2012 | e-ISSN: 1365-2966 | DOI:
The effect of the linear term on the wavelet estimator of primordial non-Gaussianity

More Like This

Show all results sharing this subject:

  • Astronomy and Astrophysics


Show Summary Details


In this work, we present constraints on different shapes of primordial non-Gaussianity using the Wilkinson Microwave Anisotropy Probe (WMAP) seven-year data and the spherical Mexican hat wavelet fnl estimator including the linear term correction. In particular, we focus on the local, equilateral and orthogonal shapes. We first analyse the main statistical properties of the wavelet estimator and show the conditions to reach optimality. We include the linear term correction in our estimators and compare the estimates with the values already published using only the cubic term. The estimators are tested with realistic WMAP simulations with anisotropic noise and the WMAP KQ 75 sky cut. The inclusion of the linear term correction shows a negligible improvement (≤1 per cent) in the error bar for any of the shapes considered. The results of this analysis show that, in the particular case of the wavelet estimator, the optimality for WMAP anisotropy levels is basically achieved with the mean subtraction, and in practical terms there is no need of including a linear term once the mean has been subtracted. Our best estimates are now , and . We have also computed the expected linear term correction for simulated Planck maps with anisotropic noise at 143 GHz following the Planck Sky Model and including a mask. The improvement achieved in this case for the local fnl error bar is also negligible (0.4 per cent).

Keywords: methods: data analysis; cosmic background radiation; cosmology: observations

Journal Article.  4224 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.