Density perturbations in the ekpyrotic scenario

Justin Khoury, Burt A. Ovrut, Paul J. Steinhardt, Neil Turok

Research output: Contribution to journalArticlepeer-review

232 Scopus citations


We study the generation of density perturbations in the ekpyrotic scenario for the early universe, including gravitational backreaction. We expose interesting subtleties that apply to both inflationary and ekpyrotic models. Our analysis includes a detailed proposal of how the perturbations generated in a contracting phase may be matched across a "bounce" to those in an expanding hot big bang phase. For the physical conditions relevant to the ekpyrotic scenario, we reobtain our earlier result of a nearly scale-invariant spectrum of energy density perturbations. We find that the perturbation amplitude is typically small, as desired to match observation.

Original languageEnglish (US)
Article number046005
JournalPhysical Review D
Issue number4
StatePublished - 2002

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)


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