Causality in relativistic quantum interactions without mediators
Abstract
We analyse the interaction between two quantum systems in spacetime and we compare two possible models to describe it: 1) a fully quantum field theoretical (QFT) description of the coupling of two quantum systems mediated by a quantum field and 2) a quantum-controlled model (qc-model), which is an effectively relativistic direct-coupling in which the interaction of two quantum systems is not mediated by a field with local quantum degrees of freedom. We show that while there are regimes where the qc-model can approximate QFT arbitrarily well, it can suffer from retrocausal effects. We discuss in what regimes those retrocausal predictions of the qc-model are non-negligible and whether they can be used to argue that gravity induced entanglement experiments can reveal genuinely quantum aspects of the gravitational interaction or not.
Cite
@article{arxiv.2412.16288,
title = {Causality in relativistic quantum interactions without mediators},
author = {Eirini C. Telali and T. Rick Perche and Eduardo Martín-Martínez},
journal= {arXiv preprint arXiv:2412.16288},
year = {2025}
}
Comments
15 pages, 4 figures, 1 appendix