Wave correlations and quantum noise in cosmology

TL;DR

This paper investigates wave noise correlations in cosmology, revealing their role in phenomena like the Casimir effect and particle creation, and analyzing their contribution to vacuum energy in expanding universe models.

Contribution

It provides a detailed analysis of wave noise correlations in non-exponentially expanding flat space and their implications for vacuum energy and cosmological constant.

Findings

Wave correlations lead to fluctuation forces such as the Casimir force.

Noise correlations contribute to vacuum energy resembling a cosmological constant.

High-frequency asymptotics of correlation spectrum are characterized in the conformal vacuum.

Abstract

Wave noise is correlated. While it may look random in space, correlations appear in space-time, because the noise is carried by wave propagation. These correlations of wave noise give rise to fluctuation forces such as the Casimir force, they are responsible for the particle creation in the dynamical Casimir effect and in the expanding universe. This paper considers the noise correlations for light waves in non-exponentially expanding flat space. The paper determines the high-frequency asymptotics of the correlation spectrum in the conformal vacuum. These noise correlations give rise to a nontrivial vacuum energy that may appear as the cosmological constant.