Preheating in derivatively coupled inflation models

Cristian Armendariz-Picon, Mark Trodden, Eric J. West

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


We study preheating in theories where the inflaton couples derivatively to scalar and gauge fields. Such couplings may dominate in, for example, models of natural inflation, in which the flatness of the inflaton potential is related to an approximate shift symmetry of the inflaton. We compare our results with previously studied models with non-derivative couplings. For sufficiently heavy scalar matter, parametric resonance is ineffective in reheating the universe, because the couplings of the inflaton to matter are very weak. If scalar matter fields are light, derivative couplings lead to long-wavelength instabilities that drive matter fields to non-zero expectation values. In this case however, long-wavelength fluctuations of the light scalar are produced during inflation, leading to a host of cosmological problems. In contrast, axion-like couplings of the inflaton to a gauge field do not lead to production of long-wavelength fluctuations during inflation. However, again because of the weakness of the couplings to the inflaton, parametric resonance is not effective in producing gauge field quanta.

Original languageEnglish (US)
Article number036
JournalJournal of Cosmology and Astroparticle Physics
Issue number4
StatePublished - 2008


  • inflation
  • physics of the early universe

ASJC Scopus subject areas

  • Astronomy and Astrophysics


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