De-Sitter Quantum Loops as the origin of Primordial Non-Gaussianities

Abstract

It was recently pointed out that in some inflationary models quantum loops containing a scalar of mass m that couples to the inflaton can be the dominant source of primordial non-Gaussianities. We explore this phenomenon in the simplest such model focusing on the behavior of the primordial curvature fluctuations for small m/H. Explicit calculations are done for the three- and four-point curvature fluctuation correlations. Constraints on the parameters of the model from the cosmic microwave background limits on primordial non-Gaussianity are discussed. The bispectrum in the squeezed limit and the trispectrum in the compressed limit are examined. The form of the n-point correlations as any partial sum of wave vectors gets small is determined.