title: Non-Gaussianity from preheating.
abstract: We consider a two-field model for inflation where the second order metric perturbations can be amplified by a parametric resonance during preheating. We demonstrate that there can arise a considerable enhancement of non-Gaussianity sourced by the local terms generated through the coupled perturbations. We argue that the non-Gaussianity parameter could be as large as f(NL) approximately 50. Our results may provide a useful test of preheating in future cosmic microwave background experiments.
authors.affiliation: Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki, Finland.
authors.forename: Kari
authors.initials: K
authors.lastname: Enqvist
authors.forename: Asko
authors.initials: A
authors.lastname: Jokinen
authors.forename: Anupam
authors.initials: A
authors.lastname: Mazumdar
authors.forename: Tuomas
authors.initials: T
authors.lastname: Multamäki
authors.forename: Antti
authors.initials: A
authors.lastname: Väihkönen