Cosmic evolution in a cyclic universe

Paul J. Steinhardt, Neil Turok

Research output: Contribution to journalArticlepeer-review

603 Scopus citations


Based on concepts drawn from the ekpyrotic scenario and M theory, we elaborate our recent proposal of a cyclic model of the universe. In this model, the universe undergoes an endless sequence of cosmic epochs which begin with the universe expanding from a "big bang" and end with the universe contracting to a "big crunch." Matching from "big crunch" to "big bang" is performed according to the prescription recently proposed with Khoury, Ovrut and Seiberg. The expansion part of the cycle includes a period of radiation and matter domination followed by an extended period of cosmic acceleration at low energies. The cosmic acceleration is crucial in establishing the flat and vacuous initial conditions required for ekpyrosis and for removing the entropy, black holes, and other debris produced in the preceding cycle. By restoring the universe to the same vacuum state before each big crunch, the acceleration ensures that the cycle can repeat and that the cyclic solution is an attractor.

Original languageEnglish (US)
Article number126003
JournalPhysical Review D
Issue number12
StatePublished - 2002

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)


Dive into the research topics of 'Cosmic evolution in a cyclic universe'. Together they form a unique fingerprint.

Cite this