Model of graceful exit in string cosmology

Ram Brustein, Richard Madden

Research output: Contribution to journalArticlepeer-review

158 Scopus citations


We construct, for the first time, a model of graceful exit transition from a dilaton-driven inflationary phase to a decelerated Friedmann-Robertson-Walker era. Exploiting a demonstration that classical corrections can stabilize a high curvature string phase while the evolution is still in the weakly coupled regime, we show that if additional terms of the type that may result from quantum corrections to the string effective action exist, and induce violation of the null energy condition, then evolution towards a decelerated Friedmann-Robertson-Walker phase is possible. We also observe that stabilizing the dilaton at a fixed value, either by capture in a potential minimum or by radiation production, may require that these quantum corrections are turned off, perhaps by nonperturbative effects or higher order contributions which overturn the null energy condition violation.

Original languageEnglish
Pages (from-to)712-724
Number of pages13
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number2
StatePublished - 1 Jan 1998

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


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