Curvature spectra and nongaussianities in the roulette inflation model

Aaron C Vincent, James M Cline
2008 Journal of High Energy Physics  
Using the gradient expansion method of Rigopoulos, Shellard and van Tent which treats cosmological perturbations as gradients on top of a homogeneous and isotropic FRW background, we study the production of nongaussianities in the roulette model of inflation. Investigating a number of trajectories within this two-field model of inflation, we find that while the superhorizon influence of the isocurvature modes on the curvature bispectrum produces nonzero contribution to f_NL, the effect is
more » ... ible next to the standard inflationary prediction |f_NL| ~ n_s - 1. This is the case in both the squeezed and equilateral configurations of the bispectrum, although the former is slightly larger in the trajectories under consideration.
doi:10.1088/1126-6708/2008/10/093 fatcat:a277mtobpbagjozkkan43sxphy