TY - JOUR
T1 - Large non-gaussianity in axion inflation
AU - Barnaby, Neil
AU - Peloso, Marco
PY - 2011/5/5
Y1 - 2011/5/5
N2 - The inflationary paradigm has enjoyed phenomenological success; however, a compelling particle physics realization is still lacking. Axions are among the best-motivated inflaton candidates, since the flatness of their potential is naturally protected by a shift symmetry. We reconsider the cosmological perturbations in axion inflation, consistently accounting for the coupling to gauge fields cφFF, which is generically present in these models. This coupling leads to production of gauge quanta, which provide a new source of inflaton fluctuations, δ φ. For c>102Mp-1, these dominate over the vacuum fluctuations, and non-Gaussianity exceeds the current observational bound. This regime is typical for concrete realizations that admit a UV completion; hence, large non-Gaussianity is easily obtained in minimal and natural realizations of inflation.
AB - The inflationary paradigm has enjoyed phenomenological success; however, a compelling particle physics realization is still lacking. Axions are among the best-motivated inflaton candidates, since the flatness of their potential is naturally protected by a shift symmetry. We reconsider the cosmological perturbations in axion inflation, consistently accounting for the coupling to gauge fields cφFF, which is generically present in these models. This coupling leads to production of gauge quanta, which provide a new source of inflaton fluctuations, δ φ. For c>102Mp-1, these dominate over the vacuum fluctuations, and non-Gaussianity exceeds the current observational bound. This regime is typical for concrete realizations that admit a UV completion; hence, large non-Gaussianity is easily obtained in minimal and natural realizations of inflation.
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U2 - 10.1103/PhysRevLett.106.181301
DO - 10.1103/PhysRevLett.106.181301
M3 - Article
C2 - 21635081
AN - SCOPUS:79960620820
SN - 0031-9007
VL - 106
JO - Physical review letters
JF - Physical review letters
IS - 18
M1 - 181301
ER -