Semiclassical analysis of the Starobinsky inflationary model

TL;DR

This paper applies semiclassical phase integral methods to analyze the Starobinsky inflation model, demonstrating accurate reproduction of the scalar power spectrum and favorable spectral index comparisons with observations.

Contribution

It introduces a third-order semiclassical phase integral approach to analyze the Starobinsky inflation model, improving accuracy over previous methods.

Findings

Semiclassical methods accurately reproduce the scalar power spectrum.

Spectral index results align well with observational data.

Comparison shows advantages over slow-roll approximation.

Abstract

In this work we study the scalar power spectrum and the spectral index for the Starobinsky inflationary model using the phase integral method up-to third-order of approximation. We show that the semiclassical methods reproduce the scalar power spectrum for the Starobinsky model with a good accuracy, and the value of the spectral index compares favorably with observations. Also, we compare the results with the uniform approximation method and the second-order slow-roll approximation.