Effects of discontinuities of the derivatives of the inflaton potential
  We study the effects of a class of features of the inflaton potential,
corresponding to discontinuties in its derivatives. We perform fully numerical
calculations and derive analytical approximations for the curvature
pertubations spectrum and the bispectrum which are in good agreement with the
numerical results.
  The spectrum of primordial perturbations has oscillations around the scale
$k_0$ which leaves the horizon at the time $\tau_0$ when the feature occurs,
with the amplitude and phase of the oscillations determined by the size and the
order of the discontinuity. The large scale bispectrum in the squeezed and
equilateral limits have a very similar form and are linearly suppressed. Both
in the squeezed and equilateral small scale limit the bispectrum has an
oscillatory behavior whose phase depends on the parameters determining the
discontinuity, and whose amplitude is inversely proportional to the scale.
Given the generality of this class of features they could be used to model or
classify phenomenologically different types of non Gaussian features
encountered in observational data such as the cosmic microwave background
radiation or large scale structure.
