Spacetime Relationalism in GR and QG

TL;DR

This paper advocates a relational view of spacetime in general relativity, proposing that spacetime geometry emerges from the material properties of gravitational fields, which may influence approaches in quantum gravity.

Contribution

It provides a philosophical foundation for spacetime relationalism, linking it to the phase space of GR and suggesting implications for quantum gravity.

Findings

Spacetime is viewed as an emergent property of gravitational fields.

The relational approach aligns with the phase space structure of GR.

Implications for quantum gravity are discussed.

Abstract

We provide here a philosophical basis for [arXiv:2012.03994, arXiv:2107.06693] based on the notion of spacetime relationalism. We argue that the view which is more cleanly compatible with GR is that in which the spacetime manifold is a relational (or 'emergent') property of the aggregate or physical sum of gravitational field portions, field that is considered material and for which spacetime geometry (in the sense of the metric properties) is one of its material properties. All of the previous philosophical notions are defined in relation to a clear ontology of material individuals, briefly described in the appendix. Furthermore, this fits well with the phase space of GR, thing that also may inform how to proceed in the quantum realm.