Inflationary axion cosmology

Michael S. Turner, Frank Wilczek

Research output: Contribution to journalArticlepeer-review

163 Scopus citations


If Peccei-Quinn (PQ) symmetry is broken after inflation, the initial axion angle is a random variable on cosmological scales; based on this fact, estimates of the relic-axion mass density give too large a value if the axion mass is less than about 10-6 eV. This bound can be evaded if the Universe underwent inflation after PQ symmetry breaking and if the observable Universe happens to be a region where the initial axion angle was atypically small, 1[ma/(10-6 eV]0.59.] We show consideration of fluctuations induced during inflation severely constrains the latter alternative.

Original languageEnglish (US)
Pages (from-to)5-8
Number of pages4
JournalPhysical Review Letters
Issue number1
StatePublished - 1991
Externally publishedYes

ASJC Scopus subject areas

  • General Physics and Astronomy


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