Department of Physics Papers

Document Type

Journal Article

Date of this Version

5-2-2008

Comments

Suggested Citation:
E.I. Buchbinder, J. Khoury and B.A. Ovrut. (2008). "Non-Gaussianities in New Ekpyrotic Cosmology." Physical Review Letters. 100, 171302.

© 2008 The American Physical Society
http://dx.doi.org/10.1103/PhysRevLett.100.171302

Abstract

The new ekpyrotic model 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 cosmic microwave background experiments. This is in contrast with slow-roll inflation, which predicts negligible non-Gaussianity. The model is also distinguishable from alternative inflationary scenarios that can yield large non-Gaussianity, such as Dirac-Born-Infeld inflation and the simplest curvatonlike models, through the shape dependence of the correlation functions. Non-Gaussianity therefore provides a distinguishing and testable prediction of New Ekpyrotic Cosmology.

 

Date Posted: 25 January 2011

This document has been peer reviewed.