Oscillations in the inflaton potential?

TL;DR

This paper investigates inflationary models with small oscillations in the inflaton potential, analyzing their effects on the primordial power spectrum and constraints from current and future cosmic microwave background data.

Contribution

It introduces a class of models with oscillatory features in the inflaton potential and assesses their detectability using CMB data from WMAP and Planck.

Findings

WMAP data constrains oscillation amplitude to less than 3 x 10^{-5}

Planck can detect oscillations roughly ten times smaller

Post-Planck experiments could further improve detection sensitivity

Abstract

We consider a class of inflationary models with small oscillations imprinted on an otherwise smooth inflaton potential. These oscillations are manifest as oscillations in the power spectrum of primordial perturbations, which then give rise to oscillating departures from the standard cosmic microwave background power spectrum. We show that current data from the Wilkinson Microwave Anisotropy Probe constrain the amplitude of a sinusoidal variation in the inflaton potential to have an amplitude less than 3 x 10^{-5}. We anticipate that the smallest detectable such oscillations in Planck will be roughly an order of magnitude smaller, with slight improvements possible with a post-Planck cosmic-variance limited experiment.