Generation of perturbation after multi-field inflation

TL;DR

This paper investigates how certain inflaton fields in multi-field inflation models can produce curvature perturbations consistent with observations through post-inflationary dynamics, using a string-inspired chaotic inflation model.

Contribution

It introduces a new scenario where specific inflaton fields generate observable curvature perturbations after inflation, expanding the understanding of multi-field inflation models.

Findings

Inflaton fields can satisfy the observed spectral index.

Post-inflationary dynamics can produce relevant curvature perturbations.

Brief discussion on non-Gaussianity and tensor-to-scalar ratio.

Abstract

We explore a new possibility that some inflaton fields in multi-field inflation models satisfy the observed value of the spectral index so that the curvature perturbation generated by them through post-inflationary dynamics may be relevant for the current observations. We illustrate this point using a simple and reasonable multi-field chaotic inflation model motivated from string theory. Possible non-Gaussianity and the tensor-to-scalar ratio are briefly addressed.