Transients in finite inflation

TL;DR

This paper investigates a finite inflation model with a kinetic-dominated initial state, comparing its predictions against Planck data for different inflationary potentials, and finds a marginally better fit than the standard slow-roll model.

Contribution

It provides a detailed numerical analysis of finite inflation with kinetic initial conditions and compares two inflationary models against observational data.

Findings

Slight improvement in data fit over standard slow-roll inflation

Numerical calculation of scalar and tensor power spectra for the models

Comparison of $m^2 \, \phi^2$ and $R+R^2$ gravity models

Abstract

We test a model of inflation with a fast-rolling kinetic-dominated initial condition against data from Planck using Markov chain Monte Carlo parameter estimation. We test both an $m^2 \phi^2$ potential and the $R+R^2$ gravity model and perform a full numerical calculation of both the scalar and tensor primordial power spectra. We find a slight (though not significant) improvement in fit for this model over the standard eternal slow-roll case.