Inflation with a class of concave inflaton potentials in Randall-Sundrum model

TL;DR

This paper explores a class of concave inflaton potentials in the Randall-Sundrum model, demonstrating better observational agreement than standard inflation and analyzing the implications for tensor-to-scalar ratios and small-field inflation.

Contribution

It introduces a new class of concave inflaton potentials in the Randall-Sundrum model and shows their compatibility with observations and implications for tensor-to-scalar ratios.

Findings

The model aligns well with observational data.

Large tensor-to-scalar ratios do not exclude small-field inflation.

Constraints on the five-dimensional Planck scale are established.

Abstract

We investigate inflation with a class of concave inflaton potentials of the form $\sim \phi^n$ $(0<n<1)$ in the Randall-Sundrum model with an infinite extra spatial dimension. We show that this class of models is much more in good agreement with observations compared to the standard inflation. We also find the range of the five-dimensional Planck scale ($M_5$) and show that large tensor-to-scalar ratios do not eliminate small-field inflation in braneworld cosmology.