Preheating with extra dimensions

Shinji Tsujikawa*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


We investigate preheating in a higher-dimensional generalized Kaluza-Klein theory with a quadratic inflaton potential V(φ) = 1/2m2φ2 including metric perturbations explicitly. The system we consider is the multi-field model where there exists a dilaton field σ which corresponds to the scale of compactifications and another scalar field χ coupled to inflaton with the interaction 1/2g2φ2χ2 + g-2φ3χ. In the case of g̃ = 0, we find that the perturbation of dilaton does not undergo parametric amplification while the χ field fluctuation can be enhanced in the usual manner by parametric resonance. In the presence of the g-2φ3χ coupling, the dilaton fluctuation in sub-Hubble scales is modestly amplified by the growth of metric perturbations for the large coupling g̃. In super-Hubble scales, the enhancement of the dilaton fluctuation as well as metric perturbations is weak, taking into account the backreaction effect of created χ particles. We argue that not only is it possible to predict the ordinary inflationary spectrum in large scales but extra dimensions can be held static during preheating in our scenario.

Original languageEnglish
Pages (from-to)XXXIII-25
JournalJournal of High Energy Physics
Issue number7 PART A
Publication statusPublished - 2000


  • Cosmology of Theories beyond the SM
  • Extra Large Dimensions
  • Physics of the Early Universe

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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