Post-inflationary Scalar Tensor Cosmology and Inflationary Parameters

TL;DR

This paper explores how scalar fields modifying pre-BBN cosmology influence inflationary predictions, notably shifting key parameters and potentially resolving tensions with observational data.

Contribution

It analyzes the impact of scalar field modifications on the number of e-foldings and inflationary predictions, providing new insights into inflationary model compatibility.

Findings

Significant shifts in inflationary parameters $(n_s, r)$ due to scalar field effects.

Positive shifts in $N_k$ help reconcile $m^{2} \

natural inflation with observational data.

Abstract

Scalar fields provide attractive modifications of pre-BBN cosmology, which have interesting implications for dark matter abundances. We analyse the effect of these modifications on the number of e-foldings between horizon exit of CMB modes and the end of inflation $(N_k)$, and examine the consequences for inflationary predictions of various models. We find significant effects in the predictions in the $(n_s, r)$ plane. For a large part of the parameter space, the shift in $N_k$ is positive; this ameliorates the tension of $m^{2} \varphi^{2}$ and natural inflation with data.