Long-range enhanced mutual information from inflation

TL;DR

This paper investigates how inflation-induced particle production enhances long-range mutual information between regions in the early universe, supporting the existence of primordial correlations relevant for primordial black holes.

Contribution

It demonstrates that inflation causes an enhancement of mutual information in a radiation-dominated universe, revealing long-range correlations from quantum effects during inflation.

Findings

Mutual information is enhanced compared to Minkowski vacuum due to inflation.

Long-range correlations exist between primordial black holes at formation.

Particle production during inflation affects quantum correlations.

Abstract

The quantum origin of cosmological primordial perturbations is a cornerstone framework in the interplay between gravity and quantum physics. In this paper we study the mutual information between two spatial regions in a radiation-dominated universe filled by a curvature perturbation field in a squeezed state. We find an enhancement with respect to the usual mutual information of the Minkowski vacuum due to momentum modes affected by particle production during inflation. This result supports our previous claim of the existence of long-range correlations between Primordial Black Holes (PBH) at formation during the radiation era.