Vacuum correlations at geodesic distance in quantum gravity

TL;DR

This paper reviews recent advances in understanding vacuum correlations in quantum gravity, highlighting their importance for physical properties like virtual excitations and continuum limits, through both perturbative and non-perturbative approaches.

Contribution

It provides a comprehensive overview of the latest methods and results in computing vacuum correlations in quantum gravity, emphasizing their physical significance.

Findings

Recent perturbative results on vacuum correlations

Non-perturbative approaches to quantum gravity correlations

Implications for continuum limits and virtual excitations

Abstract

The vacuum correlations of the gravitational field are highly non-trivial to be defined and computed, as soon as their arguments and indices do not belong to a background but become dynamical quantities. Their knowledge is essential however in order to understand some physical properties of quantum gravity, like virtual excitations and the possibility of a continuum limit for lattice theory. In this review the most recent perturbative and non-perturbative advances in this field are presented. (To appear on Riv. Nuovo Cim.)