De Sitter Quantum Loops As The Origin Of Primordial Non-gaussianities

We consider inflationary models with an additional light field and Z₂ symmetry where the dominant contribution to primordial non-Gaussianities comes from loop diagrams.We explore this phenomenon in the simplest such model and calculate 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.We also provide detailed derivation of some well-known results that are not easy to derive,such as the constraint of conformal invariance in momentum space etc.