Strings in a time-dependent orbifold

Hong Liu, Gregory Moore, Nathan Seiberg

Research output: Contribution to journalArticle

103 Scopus citations


We consider string theory in a time dependent orbifold with a null singularity. The singularity separates a contracting universe from an expanding universe, thus constituting a big crunch followed by a big bang. We quantize the theory both in light-cone gauge and covariantly. We also compute some tree and one loop amplitudes which exhibit interesting behavior near the singularity. Our results are compatible with the possibility that strings can pass through the singularity from the contracting to the expanding universe, but they also indicate the need for further study of certain divergent scattering amplitudes.

Original languageEnglish (US)
Pages (from-to)1059-1081
Number of pages23
JournalJournal of High Energy Physics
Issue number6
StatePublished - Jun 1 2002

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics


  • Bosonic Strings
  • Conformal Field Models in String Theory
  • Superstrings and Heterotic Strings

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