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arXiv · 2412.16288

Causality in relativistic quantum interactions without mediators

Eirini C. Telali·T. Rick Perche·Eduardo Martín-Martínez
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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.

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Eirini C. Telali, T. Rick Perche, Eduardo Martín-Martínez. 2024-12-20. Causality in relativistic quantum interactions without mediators. https://doi.org/10.1103/physrevd.111.085005

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