Axions and inflation: String formation during inflation

Jan, 1992
19 pages
Published in:
  • Phys.Rev.D 46 (1992) 532-538
Report number:
  • LANC-TH-92-03

Citations per year

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Abstract: (APS)
The Peccei-Quinn field ψ=reiθ2 has a Mexican hat potential 14λ(r2−fa2)2, and the axion, with the field faθ, is its Nambu-Goldstone boson. During inflation there is a quantum fluctuation in both the radial component r and in the angle θ. If the temperature after inflation is less than fa the fluctuation survives, and may be cosmologically significant. Previous investigations of this "inflationary scenario" assumed that r sits in the vacuum, leaving only the angular fluctuation. Here both fluctuations are kept, using the Langevin and Fokker-Planck equations. It is found that for fa in the usually accepted range fa≲1013 GeV, the radial fluctuation is typically big enough to take ψ over the top of the potential. In that case, strings are produced, which invalidate previous treatments of the inflationary scenario.
  • postulated particle: axion
  • inflation
  • astrophysics: string
  • Langevin equation
  • Fokker-Planck equation
  • cosmic radiation: anisotropy
  • numerical calculations