Primordial non-Gaussianities produced by features in the potential of single slow-roll inflationary models

We study the effects of a general type of features of the inflaton potential on the spectrum and bispectrum of primordial curvature perturbations. These features correspond to a discontinuity in the $n$-th order derivative of the potential which are dumped exponentially away from the value of the field where the feature happens. Interestingly we find that different values of the amplitude and of the order of the feature can lead to the same effects on the power spectrum on both large and short scales, and on the bispectrum at small scales. Only taking into account the bispectrum at large scales it is possible to resolve this degeneracy. We provide fully numerical calculations and analytical approximations for the spectrum and the bispectrum, which are in good agreement with each other. The analytical approximation allows to to determine the class of features which give the same spectrum and can only be distinguished with the bispectrum