Impact of general reionization scenarios on extraction of inflationary parameters

TL;DR

This paper investigates how different reionization scenarios influence the constraints on inflationary models, revealing that more general reionization assumptions broaden the range of viable inflaton potentials and reaffirm an upper energy limit.

Contribution

It introduces a comprehensive analysis of inflationary constraints under varied reionization models, expanding the understanding of potential shapes and bounds.

Findings

Hybrid inflation models become viable with general reionization scenarios.

The upper limit of the inflaton potential amplitude remains at 10^16 GeV.

Broader spectrum of potential shapes is allowed when relaxing reionization assumptions.

Abstract

Determination of whether the Harrison--Zel'dovich spectrum for primordial scalar perturbations is consistent with observations is sensitive to assumptions about the reionization scenario. In light of this result, we revisit constraints on inflationary models using more general reionization scenarios. While the bounds on the tensor-to-scalar ratio are largely unmodified, when different reionization schemes are addressed, hybrid models are back into the inflationary game. In the general reionization picture, we reconstruct both the shape and amplitude of the inflaton potential. We find a broader spectrum of potential shapes when relaxing the simple reionization restriction. An upper limit of $10^{16}$ GeV to the amplitude of the potential is found, regardless of the assumptions on the reionization history.