The geometry of spacetime from quantum measurements

TL;DR

This paper demonstrates how local quantum measurements can be used to reconstruct the geometry of spacetime, potentially replacing classical measurement devices in general relativity.

Contribution

It introduces a method to recover spacetime geometry solely from quantum detector measurements, bridging quantum field theory and spacetime structure.

Findings

Successfully reconstructs the spacetime metric from quantum measurements

Shows how to derive the invariant spacetime interval from detector data

Proposes quantum detectors as practical tools for measuring spacetime geometry

Abstract

We provide a setup by which one can recover the geometry of spacetime from local measurements of quantum particle detectors coupled to a quantum field. Concretely, we show how one can recover the field's correlation function from measurements on the detectors. Then, we are able to recover the invariant spacetime interval from the measurement outcomes, and hence reconstruct a notion of spacetime metric. This suggest that quantum particle detectors are the experimentally accessible devices that could replace the classical 'rulers' and 'clocks' of general relativity.