Cosmic Microwave Background Bispectrum and Slow Roll Inflation
Year: 1999
Type: preprint
Abstract: Recent tentative findings of non-Gaussian structure in the COBE-DMR dataset have triggered renewed attention to 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 Cℓ1ℓ2ℓ3 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 ℓi 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 behavior of the signal-to-(theoretical) noise ratio and demonstrate for generic inflationary models that it decreases in the limited range of small-ℓ’s considered for increasing multipole ℓ while the opposite applies for the standard Cℓ’s. Key words: cosmic microwave background- methods: analytical- cosmology: theory- large scale structures of Universe- early Universe. 1
Authors: Ro Gangui, Jérôme Martin
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3104637062