Xème Ecole de Cosmologie
5-10 juillet 2010 IESC, Cargèse
Le fond diffus cosmologique à haute résolution angulaire
Hunting for Primordial non-Gaussianity in the Cosmic
Microwave Background 
Eiichiroo KOMATSU
Department of Astronomy, The University of Texas at
Austin
|
Chapitres
du
Cours
Résumé Since
the
first
limit
on the (local)
primordial non-Gaussianity parameter, fNL, was obtained from COBE data
in 2002, observations of the CMB have been playing a central role in
constraining the amplitudes of various forms of non-Gaussianity in
primordial fluctuations. The current 68% limit from the 7-year WMAP
data is fNL=32+/-21, and the Planck satellite is expected to reduce the
uncertainty by a factor of four in a few years from now. If
fNL>>1 is found by Planck with high statistical significance, all
single-field models of inflation would be ruled out. Moreover, if the
Planck satellite finds fNL=30, then it would be able to test a broad
class of multi-field models using the four-point function (trispectrum)
test of tauNL>=(6fNL/5)^2. In this lecture, we review the basics of
Gaussian and non-Gaussian statistics, learn the significance (why
bispectrum and trispectrum), methods (optimal estimator), results (WMAP
7-year), and challenges (secondary anisotropy, second-order effect, and
foreground) of measuring primordial non-Gaussianity from the CMB data.
Bibliographie
|
