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arXiv · 0710.5172

Non-Gaussianities in New Ekpyrotic Cosmology

Evgeny I. Buchbinder·Justin Khoury·Burt A. Ovrut
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Abstract

New Ekpyrotic Cosmology is an alternative scenario of the early universe which relies on a phase of slow contraction before the big bang. We calculate the 3-point and 4-point correlation functions of primordial density perturbations and find a generically large non-Gaussian signal, just below the current sensitivity level of CMB experiments. This is in contrast with slow-roll inflation, which predicts negligible non-Gaussianity. The model is also distinguishable from alternative inflationary scenarios that yield large non-Gaussianity, such as DBI inflation and the simplest curvaton-like models, through the shape dependence of the correlation functions. Non-Gaussianity therefore provides a distinguishing and testable prediction of New Ekpyrotic Cosmology.

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Evgeny I. Buchbinder, Justin Khoury, Burt A. Ovrut. 2008-04-24. Non-Gaussianities in New Ekpyrotic Cosmology. https://doi.org/10.1103/physrevlett.100.171302

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