DBI in the Sky

TL;DR

This paper investigates a new inflation model called 'D-cceleration' that predicts observable non-Gaussianity and a large tensor component in the CMBR, providing a testable alternative to slow roll inflation.

Contribution

It introduces a D-cceleration inflation model derived from strong coupling quantum effects, predicting observable non-Gaussianity and tensor signals, distinguishing it from traditional models.

Findings

Model has a strict lower bound on non-Gaussianity detectable in CMBR.

Predicts a large observable tensor component in the CMBR spectrum.

Falsifiable through current and future cosmological observations.

Abstract

We analyze the spectrum of density perturbations generated in models of the recently discovered "D-cceleration" mechanism of inflation. In this scenario, strong coupling quantum field theoretic effects sum to provide a DBI-like action for the inflaton. We show that the model has a strict lower bound on the non-Gaussianity of the CMBR power spectrum at an observable level, and is thus falsifiable. This in particular observationally distinguishes this mechanism from traditional slow roll inflation generated by weakly interacting scalar fields. The model also favors a large observable tensor component to the CMBR spectrum.