Physics – High Energy Physics – High Energy Physics - Theory
Scientific paper
2009-01-26
JCAP 0905:018,2009
Physics
High Energy Physics
High Energy Physics - Theory
41 pages, 7 figures, 2 appendices. Added some clarifications and comments, additional references, to appear in JCAP
Scientific paper
10.1088/1475-7516/2009/05/018
Modifications of the initial-state of the inflaton field can induce a departure from Gaussianity and leave a testable imprint on the higher order correlations of the CMB and large scale structures in the Universe. We focus on the bispectrum statistics of the primordial curvature perturbation and its projection on the CMB. For a canonical single-field action the three-point correlator enhancement is localized, maximizing in the collinear limit, corresponding to enfolded or squashed triangles in comoving momentum space. We show that the available local and equilateral template are very insensitive to this localized enhancement and do not generate noteworthy constraints on initial-state modifications. On the other hand, when considering the addition of a dimension 8 higher order derivative term, we find a dominant rapidly oscillating contribution, which had previously been overlooked and whose significantly enhanced amplitude is independent of the triangle under consideration. Nevertheless, the oscillatory nature of (the sign of) the correlation function implies the signal is nearly orthogonal to currently available observational templates, strongly reducing the sensitivity to the enhancement. Constraints on departures from the standard Bunch-Davies vacuum state can be derived, but also depend on the next-to-leading terms. We emphasize that the construction and application of especially adapted templates could lead to CMB bispectrum constraints on modified initial states already competing with those derived from the power spectrum.
Corasaniti Pier Stefano
der Schaar Jan Pieter van
Meerburg Pieter Daniel
No associations
LandOfFree
Signatures of Initial State Modifications on Bispectrum Statistics does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Signatures of Initial State Modifications on Bispectrum Statistics, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Signatures of Initial State Modifications on Bispectrum Statistics will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-372369