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arXiv:2311.03428 · The European Physical Journal H

Note on episodes in the history of modeling measurements in local spacetime regions using QFT

Doreen Fraser, Maria Papageorgiou

Published Nov 27, 2023• 6 citations
arXivHTMLPDF
DOI
10.1140/epjh/s13129-023-00064-1

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I take non-locality to be the Michaelson Morley experiment of the early 21st Century, assume its universal validity, and try to derive its consequences. Spacetime, with its locality, cannot be fundamental, but must be emergent from entangled coherent quantum variables and their behaviors. Two immediate consequences are: i. If we start with non-locality, we need not explain non-locality. We must instead explain an of locality and spacetime. ii. There can be no of spacetime without matter. These propositions flatly contradict General Relativity, which is foundationaly local, can be formulated without matter, and where there is no emergence of spacetime. If true, then quantum gravity cannot be a minor alteration of General Relativity, but must demand its deep reformulation. This will lead to: Matter not only deforms spacetime, but creates spacetime. This quantum creation of spacetime consists in: i. Fully non-local entangled coherent quantum variables. ii. The onset of locality via decoherence. iii. A metric in Hilbert Space among entangled quantum variables by the sub-additive von Neumann Entropy between pairs of variables. iv. Mapping from metric distances in Hilbert Space to metric distances in classical spacetime by episodic actualization events. v. Discrete spacetime is the relations among these discrete actualization events. vi. Now is the shared moment of actualization of one among the entangled variables when the amplitudes of the remaining entangled variables change instantaneously. vii. The discrete, successive, episodic, irreversible actualization events constitute a quantum arrow of time. viii. The arrow of time history of these events is recorded in the very structure of the spacetime constructed. ix. Actual Time is a succession of two or more actual events. Relation to Causal Set Theory, faithful Lorentzian manifolds and light cones are discussed.
We present a non-perturbative method through which local probes can access the two-point function of a quantum field within a region of spacetime. By considering a lattice of gapless particle detectors, we identified the probe observables that encode the field's two-point function. We quantify the discrepancies introduced by physical finite-sized interaction regions by performing a spacetime multipole expansion of the smeared two-point function. Our protocol expresses the two-point function entirely in terms of measurable detectors correlations, providing an operational notion of states in QFT.