Gravity-Matter Entanglement in Regge Quantum Gravity

TL;DR

This paper explores how entanglement between gravity and matter in Regge quantum gravity states supports the idea of emergent spacetime and may influence fundamental principles like the weak equivalence principle.

Contribution

It demonstrates that Hartle-Hawking states in Regge quantum gravity inherently contain gravity-matter entanglement, offering insights into emergent spacetime and potential physical corrections.

Findings

Gravity-matter entanglement is generic in Hartle-Hawking states.

Entanglement suggests the impossibility of localized matter in a point of space.

Potential corrections to the weak equivalence principle due to entanglement.

Abstract

We argue that Hartle-Hawking states in the Regge quantum gravity model generically contain non-trivial entanglement between gravity and matter fields. Generic impossibility to talk about "matter in a point of space" is in line with the idea of an emergent spacetime, and as such could be taken as a possible candidate for a criterion for a plausible theory of quantum gravity. Finally, this new entanglement could be seen as an additional "effective interaction", which could possibly bring corrections to the weak equivalence principle.