Non-Gaussianity for a two component hybrid model of inflation

Abstract

We consider a hybrid model of inflation, in which two fields drive inflation. Ourresults show that, if the parameters are finely tuned, this model may generate anobservable non-Gaussian contribution to the curvature spectrum, within the limitsallowed by the recent WMAP year three data. We show that if one field has a massηϕ<0 and an initial valueϕ*<0.025Mpl, while the other fieldhas a mass ησ>0 and aninitial field value 0.45Mpl<σ≤Mpl, then the non-Gaussianity is observable with , but that fNL becomes much less than the observable limit should we take both masses to have the samesign, or if we loosened the constraints on the initial field values.