标题： 事件是什么不是：揭开量子理论和引力中事件身份的面纱 显示英文标题

标题： What an event is not: unravelling the identity of events in quantum theory and gravity

摘要： 我们探讨了量子物理与引力交叉领域中的事件概念，这些概念受到近期关于半经典时空叠加研究的启发。 通过各种实验和思想实验——从衰变原子到双缝实验，再到量子开关——我们分析了哪些属性可以以及不能用于在这些非经典背景下定义事件。 我们的发现表明，事件具有操作性的、依赖于上下文的定义，强调了可以通过这些属性来访问事件而不会破坏或改变观察到的现象。 我们讨论了这种对事件的理解对于不定因果关系以及在魏格纳的朋友思想实验中事件的非绝对性的影响。 这些发现为在量子时空中发展事件的概念提供了第一步。 显示英文摘要

摘要： We explore the notion of events at the intersection between quantum physics and gravity, inspired by recent research on superpositions of semiclassical spacetimes. By going through various experiments and thought experiments -- from a decaying atom, to the double-slit experiment, to the quantum switch -- we analyse which properties can and cannot be used to define events in such non-classical contexts. Our findings suggest an operational, context-dependent definition of events which emphasises that their properties can be accessed without destroying or altering observed phenomena. We discuss the implications of this understanding of events for indefinite causal order as well as the non-absoluteness of events in the Wigner's friend thought experiment. These findings provide a first step for developing a notion of event in quantum spacetime.