REVIEW 10 cited by
Quantum fields and local measurements
Not yet reviewed by Pith; the record is open.
This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.
SPECIMEN: schema-true, not a live event
T0 review · schema-true
One-sentence machine reading of the paper's core claim.
pith:XXXXXXXX · record.json · timestamp
read the original abstract
The measurement process is considered for quantum field theory on curved spacetimes. Measurements are carried out on one QFT, the "system", using another, the "probe" via a dynamical coupling of "system" and "probe" in a bounded spacetime region. The resulting "coupled theory" determines a scattering map on the uncoupled combination of the "system" and "probe" by reference to natural "in" and "out" spacetime regions. No specific interaction is assumed and all constructions are local and covariant. Given any initial probe state in the "in" region, the scattering map determines a completely positive map from "probe" observables in the "out" region to "induced system observables", thus providing a measurement scheme for the latter. It is shown that the induced system observables may be localized in the causal hull of the interaction coupling region and are typically less sharp than the probe observable, but more sharp than the actual measurement on the coupled theory. Post-selected states conditioned on measurement outcomes are obtained using Davies-Lewis instruments. Composite measurements involving causally ordered coupling regions are also considered. Provided that the scattering map obeys a causal factorization property, the causally ordered composition of the individual instruments coincides with the composite instrument; in particular, the instruments may be combined in either order if the coupling regions are causally disjoint. This is the central consistency property of the proposed framework. The general concepts and results are illustrated by an example in which both "system" and "probe" are quantized linear scalar fields, coupled by a quadratic interaction term with compact spacetime support. System observables induced by simple probe observables are calculated exactly, for sufficiently weak coupling, and compared with first order perturbation theory.
Forward citations
Cited by 10 Pith papers
-
Gravitational null rays: Covariant Quantization and the Dressing Time
Gravitational null rays are quantized in a diffeomorphism-covariant way using the gravitational dressing time as quantum reference frame, producing a Virasoro crossed-product algebra of gauge-invariant observables.
-
Measurement and preparation protocols for quantum field theory on curved spacetimes
All local observables of the real Klein-Gordon field can be measured by compactly coupled probes, and arbitrary given Hadamard states can be prepared as uncorrelated local product states.
-
Causal measurement in quantum field theory: spacetime
A framework and explicit construction enables causal regularized measurements of spacetime-localized observables in bosonic QFT, with self-backreaction and induced future correlations.
-
Foundations of Relational Quantum Field Theory I: Scalars
A relational quantum field theory for scalars is built from Poincaré-covariant quantum reference frames, yielding local observables and fields that satisfy causality and reproduce key Wightman and Algebraic QFT properties.
-
Localization and anomalous reference frames in gravity
Constructs a phase space for gravitational degrees of freedom on null ray segments with commuting localized observables via edge modes and dressing time, then introduces an effective classical theory with Virasoro def...
-
Measurements in stochastic gravity and thermal variance
Thermal photon fluctuations in a curved spacetime generate metric variance that, in the Fewster-Verch measurement scheme, equals the stochastic gravity noise kernel exactly.
-
Polarisation sets of Green operators for normally hyperbolic equations
Computes polarisation sets for kernels of advanced/retarded Green operators of normally hyperbolic operators and applies the result to close a gap for the Proca equation.
-
Phenomenological constraints on "impossible" measurements
The non-relativistic version of Sorkin's paradoxical measurement scenario has explicit bounds on signaling, with conditions identified for zero extraneous signaling.
-
Schroedinger's Equation at 100: The Wave Picture That Helped and Possibly Hurt
Schrödinger's wave picture aided early quantum calculations but seeded lasting problems by encouraging literal physical interpretations of the wave function that conflict with its configuration-space nature and with B...
-
Rethinking quantum information in gravity and fields
The paper organizes important open questions in quantum gravity and quantum information into four themes without presenting new results or derivations.
Discussion (0). Sign in to comment.