Spinodal effect in the natural inflation model

Shinji Tsujikawa*, Takashi Torii

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


Recently, Cormier and Holman pointed out that fluctuations of an inflaton field φ are significantly enhanced in the model of spinodal inflation with a potential V(φ) for which the second derivative V(2)(φ) changes sign. As an application of this model, we investigate particle production in the natural inflation model with a potential V(φ)=m4[1 + cos(φ/f)] by making use of the Hartree approximation. For typical mass scales f ∼mpl∼1019 GeV and m∼mGUT∼1016 GeV, we find that the growth of fluctuations relevantly occurs for the initial value of inflaton φ(0)≲0.1mpl. Especially for φ(0)≲10-6mpl, maximum fluctuations are so large that secondary inflation takes place by produced fluctuations. In this case, the achieved number of e-foldings becomes much larger than in the case where an effect of spinodal instability is neglected.

Original languageEnglish
Article number043505
Pages (from-to)1-9
Number of pages9
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number4
Publication statusPublished - 2000 Aug 15

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


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