Large Nongaussianity in Axion Inflation

Understand

The inflationary paradigm has enjoyed phenomenological success, however, a compelling particle physics realization is still lacking.

• The key obstruction is that the requirement of a suitably flat scalar potential is sensitive to Ultra-Violet (UV) physics.
• Axions are among the best-motivated inflaton candidates, since the flatness of their potential is naturally protected by a shift symmetry.
• We re-consider the cosmological perturbations in axion inflation, consistently accounting for the coupling to gauge fields \phi F \tilde{F}, which is generically present in these models.