Scale Dependent Local Non-Gaussianity from Loops

Original · EN

We analyze multi-field inflationary systems which yield strongly scale dependent non-Gaussianity with a shape that is very close to the local shape. As in usual multi-field models, the non-Gaussianity arises from the non-linear transfer of scalar field fluctuations to curvature perturbations. Here we consider models in which higher order terms (loops) dominate over the lowest order source of non-linearity. The magnitude of non-Gaussianity depends on an infrared cutoff which is determined by our observational probes measuring non-Gaussianity. In our models, the running is positive and large (nNG 0.2) on CMB scales. The magnitude of the bispectrum is maximally of order O(100), and grows on small scales. This can lead to interesting signals for large scale structure.