Does gravity-mediated entanglement prove the gravitational field is quantum? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
Does gravity-mediated entanglement prove the gravitational field is quantum?
Plain
The standard argument says a classical go-between cannot create entanglement, so seeing it would prove gravity quantum. A 2025 paper argues that classical gravity acting on quantum matter fields can still create some entanglement through virtual matter particles (short-lived intermediate states), so the inference is disputed.
Precise · changed · core
Revision 1: The LOCC argument (local operations and classical communication cannot create entanglement) assumes the gravitational mediator acts as a classical channel. Determine under which explicit assumptions (locality, field-theoretic matter, linearity) observed entanglement at the rate $\phi = G m^2 t/(\hbar d)$ excludes classical gravity, and compute the entanglement producible by semiclassical or stochastic classical gravity coupled to quantum-field matter, which Aziz and Howl find enters at higher order in G and grows with mass toward the Planck mass (about 2e-5 g).
Revision 2: The LOCC argument (local operations and classical communication cannot create entanglement) assumes the gravitational mediator acts as a classical channel. Determine under which explicit assumptions (locality, field-theoretic matter, linearity) observed entanglement at the rate $\phi = G m^2 t/(\hbar d)$ excludes classical gravity, and compute the entanglement producible by semiclassical or stochastic classical gravity coupled to quantum-field matter, which Aziz and Howl find enters at higher order in G and grows with mass toward the Planck mass (about $2 \times 10^{-5}$ g).
Settled by
A theorem stating which classes of classical gravity models a given entanglement measurement excludes, with parameter regimes where classical contributions are provably negligible.
Kind
well-posed
Answer type
classification
References
(empty)
Literature status
contested
Status note
Aziz and Howl (Nature 2025, arXiv:2510.19714) argued that classical gravity with quantum-field matter produces entanglement, reopening the interpretation of the proposed experiments.
Posed since
2017

Decisions