On the proper treatment of massless fields in Euclidean de Sitter space

TL;DR

This paper addresses infrared divergences in massless field calculations in Euclidean de Sitter space, demonstrating that proper treatment of the constant mode yields a well-defined perturbation theory.

Contribution

It introduces a correct quantization method for massless fields in Euclidean de Sitter space, resolving infrared divergence issues present in previous approaches.

Findings

Infrared divergences are due to improper handling of the constant mode.

Proper quantization removes divergences and allows for calculable perturbation expansions.

First nontrivial loop correction computed successfully in a massless scalar quartic theory.

Abstract

We analyze infrared divergences arising in calculations involving light and massless fields in de Sitter space. We show that these arise from an incorrect treatment of the constant mode of the field, and show that a correct quantization leads to a well-defined and calculable perturbation expansion. We illustrate this by computing the first nontrivial loop correction in a theory of a massless scalar field with a quartic interaction.