Curvatons and inhomogeneous scenarios with deviation from slow-roll

TL;DR

This paper investigates how deviations from slow-roll during inflation influence the spectral index of curvature perturbations, exploring implications for various inflationary scenarios and their ability to match observed spectral index features.

Contribution

It analyzes the impact of slow-roll deviations on the spectral index within different inflationary models, including curvatons and inhomogeneous scenarios.

Findings

Deviation from slow-roll can significantly alter the spectral index.

The model can potentially explain the observed spectral index features.

Implications for the viability of certain inflationary mechanisms.

Abstract

The spectral index is studied at the point where scalar fields deviate from slow-roll during inflation. Considering the deviation that may cause a significant difference to the time derivative of the Hubble parameter and also to the terms in the evolution equation, we show how the deviation affects the spectral index of the curvature perturbations. Considering conventional inflation, curvatons and other inhomogeneous scenarios as mechanisms for generating the cosmological perturbation, we examine whether the spectral index induced by the deviation from the standard slow-roll can explain the spectral index n-1>0 at k=0.002/Mpc while keeping n-1<0 at a smaller scale.