Non-Gaussianity and Loop Corrections in a Quadratic Two-Field Slow-Roll Model of Inflation. Part I

Abstract

In this paper it is shown that it is possible to attain a high level of non-gaussianity in a particular quadratic two-field slow-roll model of inflation by taking care of loop corrections both in the spectrum and the bispectrum. A big fNL is obtained even if ζis generated during inflation. Five issues are in consideration when constraining the available parameter space: 1. we must be sure that we are in a perturbative regime; 2. We must apply the correct condition about the (possible) loop dominance in Bζor Pζ; 3. we must satisfy the spectrum normalisation condition; 4. We must satisfy the spectral tilt constraint; 5. we must have enough inflation to solve the horizon problem.