标题： 相对论量子相互作用中的因果性，无中介者 显示英文标题

标题： Causality in relativistic quantum interactions without mediators

摘要： 我们分析了时空中的两个量子系统之间的相互作用，并比较了两种可能的模型来描述这种相互作用：1）通过量子场介导的两个量子系统的完全量子场论（QFT）耦合描述；2）一种量子控制模型（qc模型），这是一种有效的相对论直接耦合，其中两个量子系统的相互作用并非由具有局域量子自由度的场所介导。 我们表明，尽管存在某些区域，qc模型可以任意逼近QFT，但它可能会遭受回溯因果效应。 我们讨论了在哪些区域qc模型的这些回溯因果预测是不可忽略的，并探讨它们是否可用于论证引力诱导的纠缠实验能否揭示引力相互作用的真正量子特性。 显示英文摘要

摘要： 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.