We provide analytic solutions for the power spectrum and bispectrum ofcurvature fluctuations produced by a step feature in the inflaton potential,valid in the limit that the step is short and sharp. In this limit, thebispectrum is strongly scale dependent and its effective non-linearity attainsa large oscillatory amplitude. The perturbations to the curvature powerspectrum, on the other hand, remain a small component on top of the usualspectrum of fluctuations generated by slow roll. We utilize our analyticsolutions to assess the observability of the predicted non-Gaussian signaturesand show that, if present, only very sharp steps on scales larger than ~ 2 Gpcare likely to be able to be detected by Planck. Such features are not onlyconsistent with WMAP7 data, but can also improve its likelihood by 2 Delta ln L~ 12 for two extra parameters, the step location and height. If thisimprovement were due to a slow roll violating step as considered here, abispectrum or corresponding polarization power spectrum detection would providedefinitive checks as to its primordial origin.
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