The large-scale structure of vacuum

TL;DR

This paper proposes that the quantum vacuum may have a large-scale structure resembling dark matter, with vacuum energy perturbations capable of supporting galaxy and cluster formation.

Contribution

It introduces a model where vacuum energy behaves as non-relativistic matter at late times, supporting structure formation similar to cold dark matter.

Findings

Vacuum energy can behave as non-relativistic matter.

Vacuum supports perturbations with negligible sound speed.

Vacuum structure could seed galaxy and cluster formation.

Abstract

The vacuum state in quantum field theory is known to exhibit an important number of fundamental physical features. In this work we explore the possibility that this state could also present a non-trivial space-time structure on large scales. In particular, we will show that by imposing the renormalized vacuum energy-momentum tensor to be conserved and compatible with cosmological observations, the vacuum energy of sufficiently heavy fields behaves at late times as non-relativistic matter rather than as a cosmological constant. In this limit, the vacuum state supports perturbations whose speed of sound is negligible and accordingly allows the growth of structures in the vacuum energy itself. This large-scale structure of vacuum could seed the formation of galaxies and clusters very much in the same way as cold dark matter does.