The Komatsu Spergel Wandelt estimator for oscillations in the cosmic microwave background bispectrum

¹ Sorbonne Universités, UPMC Univ. Paris 06, UMR 7095, Institut d’Astrophysique de Paris, 75014 Paris, France
e-mail: munchmey@iap.fr
² CNRS, UMR 7095, Institut d’Astrophysique de Paris, 75014 Paris, France
³ Lagrange Institute (ILP) 98bis boulevard Arago, 75014 Paris, France
⁴ Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
⁵ Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
⁶ Paris Centre for Cosmological Physics and Laboratoire AstroParticule et Cosmologie, Université Paris 7-Denis Diderot, 75205 Paris Cedex 13, France
⁷ African Institute for Mathematical Sciences, 7945 Muizenberg, South Africa

Received: 9 May 2014
Accepted: 1 August 2014

Abstract

Oscillating shapes of the primordial bispectrum are present in many inflationary models. The Planck experiment has recently published measurements of oscillating shapes, which were, however, limited to the efficient frequency range of the used analysis method. Here, we study the Komatsu Spergel Wandelt (KSW) estimator for oscillations in the cosmic microwave background bispectrum, that examines arbitrary oscillation frequencies for separable oscillating bispectrum shapes. We study the precision with which amplitude, phase, and frequency can be determined with our estimator. An examination of the three-point function in real space gives further insight into the estimator.