On the power spectrum generated during inflation

TL;DR

This paper reviews different methods for calculating the curvature power spectrum during inflation, clarifies the validity of the standard expression, and emphasizes its importance for connecting inflationary models with observations.

Contribution

It resolves disagreements over the curvature power spectrum calculation during inflation and defends the validity of the standard expression.

Findings

The standard expression for the power spectrum is valid.

Discussions clarify different viewpoints on spectrum evaluation.

Highlights importance for linking inflation to observations.

Abstract

Recently there have been differing viewpoints on how to evaluate the curvature power spectrum generated during inflation. Since the primordial curvature power spectrum is the seed for structure formation and provides a link between observations and inflationary parameters, it is important to resolve any disagreements over the expression for the power spectrum. In this article we discuss these differing viewpoints and indicate issues that are relevant to both approaches. We then argue why the standard expression is valid.