Bucher, M (reprint author), Univ Paris Diderot, CNRS IN2P3, CEA Irfu, Observ Paris,Sorbonne Paris Cite,APC,AstroParticu, 10 Rue Alice Domon & Leonie Duquet, F-75205 Paris 13, France.
文章类型:
Article
英文摘要:
We describe the details of the binned bispectrum estimator as used for the official 2013 and 2015 analyses of the temperature and polarization CMB maps from the ESA Planck satellite. The defining aspect of this estimator is the determination of a map bispectrum (3-point correlation function) that has been binned in harmonic space. For a parametric determination of the non-Gaussianity in the map (the so-called f(NL), parameters), one takes the inner product of this binned bispectrum with theoretically motivated templates. However, as a complementary approach one can also smooth the binned bispectrum using a variable smoothing scale in order to suppress noise and make coherent features stand out above the noise. This allows one to look in a model-independent way for any statistically significant bispectral signal. This approach is useful for characterizing the bispectral shape of the galactic foreground emission, for which a theoretical prediction of the bispectral anisotropy is lacking, and for detecting a serendipitous primordial signal, for which a theoretical template has not yet been put forth. Both the template-based and the non-parametric approaches are described in this paper.
Bucher, M,Racine, B,van Tent, B. The binned bispectrum estimator: template-based and non-parametric CMB non-Gaussianity searches[J]. JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS,2016(5):55.
