Department of Physics Papers
Document Type
Journal Article
Date of this Version
7-11-2011
Abstract
We derive all single-field cosmologies with unit sound speed that generate scale invariant curvature perturbations on a dynamical attractor background. We identify three distinct phases: slow-roll inflation; a slowly contracting adiabatic ekpyrotic phase, described by a rapidly varying equation of state; and a novel adiabatic ekpyrotic phase on a slowly expanding background. All of these yield identical power spectra. The degeneracy is broken at the 3-point level: unlike the nearly Gaussian spectrum of slow-roll inflation, adiabatic ekpyrosis predicts large non-Gaussianities on small scales.
Date Posted: 14 July 2011
This document has been peer reviewed.
Comments
Suggested Citation:
Khoury, J. and Miller, G.E.J. (2011). Towards a cosmological dual to inflation. Physical Review D 84, 023511.
© 2011 American Physical Society
http://dx.doi.org/10.1103/PhysRevD.84.023511