https://doi.org/10.1140/epjc/s10052-015-3733-x
Regular Article - Theoretical Physics
Effects of discontinuities of the derivatives of the inflaton potential
1
Instituto de Fisica, Universidad de Antioquia, A.A.1226, Medellin, Colombia
2
Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, Japan
3
Department of Physics, University of Crete, 71003, Heraklion, Greece
* e-mail: aer@physics.uoc.gr
Received:
22
April
2015
Accepted:
15
October
2015
Published online:
12
December
2015
We study the effects of a class of features of the inflaton potential, corresponding to discontinuities in its derivatives. We perform fully numerical calculations and derive analytical approximations for the curvature perturbations spectrum and the bispectrum which are in good agreement with the numerical results. The spectrum of primordial perturbations has oscillations around the scale 
which leaves the horizon at the time 
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 the 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.
© The Author(s), 2015
