Constraining Monodromy Inflation

TL;DR

This paper uses WMAP data to constrain monodromy inflation models, exploring potential periodic modulations in the inflaton potential and their implications for primordial non-Gaussianity detection.

Contribution

It identifies possible periodic modulations in the inflationary potential that improve data fit and discusses their implications for non-Gaussianity detection in future CMB observations.

Findings

Two periodic modulations improve the fit to WMAP data.

Unmodulated potential is mildly favored by model selection.

Potential for detectable non-Gaussianity in upcoming CMB data.

Abstract

We use cosmic microwave background (CMB) data from the 9-year WMAP release to derive constraints on monodromy inflation, which is characterized by a linear inflaton potential with a periodic modulation. We identify two possible periodic modulations that significantly improve the fit, but it is unclear whether this improvement is associated with a "signal" or with the scatter in the measured angular power spectrum. The unmodulated potential is mildly favored by standard model selection criteria. A modulated inflationary potential can generate substantial primordial non-Gaussianity, of a specific and characteristic form. For the best-fit parameters to the WMAP angular power spectrum, the corresponding non-Gaussianity might be detectable in upcoming CMB data, allowing nontrivial consistency checks on the predictions of a modulated inflationary potential.