Hybrid Inflation Revisited in Light of WMAP5

Understand

We study the effects of including one-loop radiative corrections in a non-supersymmetric hybrid inflationary model.

• These corrections can arise from Yukawa couplings between the inflaton and right-handed neutrinos, and induce a maximum in the potential which admits hilltop-type solutions in addition to the standard hybrid solutions.
• We obtain a red-tilted spectral index $n_s$, consistent with WMAP5 data, for sub-Planckian values of the field.
• This is in contrast to the tree level hybrid analysis, in which a red-tilted spectrum is achieved only for trans-Planckian values of the field.