Inflation driven by a holographic energy density

TL;DR

This paper proposes a holographic energy density model for inflation, incorporating ultraviolet corrections, and constrains its parameters using Planck 2018 observational data.

Contribution

It introduces a modified holographic inflation model based on the G-O cutoff with UV corrections and derives constraints on its parameters from observational data.

Findings

Derived algebraic equation for the Hubble parameter during inflation

Calculated inflationary observables like spectral indices and tensor-to-scalar ratio

Provided parameter constraints consistent with Planck 2018 data

Abstract

In this letter we study a model of inflation in which the inflationary regimen comes from a type of holographic energy density. In particular, we consider the Granda-Oliveros proposal for the holographic energy density, which contains two free dimensionless parameters, $\alpha$ and $\beta$. This holographic energy density is associated to the so-called Granda-Oliveros infrared cutoff (G-O cutoff). Additionally, since in the inflationary regimen the energy scales are very high, it is necessary to modify the G-O cutoff taking into account a correction due to the ultraviolet cutoff. In this way, we obtain an algebraic equation which implicitly includes the Hubble parameter (as a function of e-folding number, $N$) and from this, we calculate the Hubble slow-roll parameters and the values of the inflationary observables: the scalar spectral index of the curvature perturbations and its running, the tensor spectral index and the tensor-to-scalar ratio. Finally, since the values for these inflationary observables are known (Planck 2018 observations), we present constraints on the parameters $\alpha$ and $\beta$ to make this a viable model.