Cosmic microwave background bispectrum and slow-roll inflation

被引:50
作者
Gangui, A [1 ]
Martin, J [1 ]
机构
[1] Observ Paris, Dept Astrophys Realat & Cosmol, CNRS, UMR 8629, F-92195 Meudon, France
关键词
methods : analytical; cosmic microwave background; cosmology : theory; early Universe; large-scale structure of Universe;
D O I
10.1046/j.1365-8711.2000.03210.x
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Recent tentative findings of non-Gaussian structure in the COBE-DMR data set have triggered renewed attention on candidate models from which such intrinsic signature could arise. In the framework of slow-roll inflation with built-in non-linearities in the inflaton field evolution, we present expressions for both the cosmic microwave background (CMB) skewness and the full angular bispectrum C-l1l2l3 in terms of the slow-roll parameters. We use an estimator for the angular bispectrum recently proposed in the literature and calculate its variance for an arbitrary l(i) multipole combination. We stress that a real detection of non-Gaussianity in the CMB would imply that an important component of the anisotropies arises from processes other than primordial quantum fluctuations. We further investigate the behaviour of the signal-to-(theoretical) noise ratio and demonstrate for generic inflationary models that it decreases in the limited range of small ls considered for increasing multipole l, while the opposite applies for the standard C(l)s.
引用
收藏
页码:323 / 330
页数:8
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