Density perturbations in the ekpyrotic Universe and string-inspired generalizations

Shinji Tsujikawa*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

63 Citations (Scopus)


We study density perturbations in several cosmological models motivated by string theory. The evolution and the spectra of curvature perturbations R are analyzed in the ekpyrotic scenario and nonsingular string cosmologies. We find that these string-inspired models generally exhibit blue spectra in contrast to standard slow-roll inflationary scenarios. We also clarify the parameter range where R is enhanced on superhorizon scales.

Original languageEnglish
Pages (from-to)179-185
Number of pages7
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Issue number3-4
Publication statusPublished - 2002
Externally publishedYes

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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