CosmologyOpen Access
NON-GAUSSIANITY FROM THE BISPECTRUM IN GENERAL MULTIPLE FIELD INFLATION
https://doi.org/10.1142/S2010194511000286Cited by:0 (Source: Crossref)
Abstract
We study the non-gaussianity from the bispectrum in multi-field inflation models with a general kinetic term. The models include the multi-field K-inflation and the multi-field Dirac-Born-Infeld (DBI) inflation as special cases. We derive the three-point function for the curvature perturbation which depends on both adiabatic and entropy perturbations, in the small sound speed limit and at leading order in the slow-roll expansion. The contribution from the entropy perturbations has a different momentum dependence if the sound speed for the entropy perturbations is different from the adiabatic one, which provides a possibility to distinguish the multi-field models from single field models.
