标题： 宏观叠加和黑洞幺正性 显示英文标题

标题： Macroscopic superpositions and black hole unitarity

摘要： 我们讨论黑洞信息问题，包括最近提出的观点，即幺正性要求视界火墙，强调退相干和宏观叠加态的作用。 我们将大黑洞的形成和蒸发视为一个量子振幅，并注意到在中间阶段（例如，Page时间之后），该振幅是宏观上不同的（并已退相干）时空的叠加态，黑洞本身在不同分支上处于不同的位置。 小但半经典的观察者（他们自身也是量子振幅的一部分）在某一分支上落入黑洞时，在其他分支上会完全错过黑洞并最终到达未来无限远。 这一观察可以调和下落观察者的主观体验与幺正性。 我们还讨论了信息问题的nice slice表述及其对互补性的意义。 显示英文摘要

摘要： We discuss the black hole information problem, including the recent claim that unitarity requires a horizon firewall, emphasizing the role of decoherence and macroscopic superpositions. We consider the formation and evaporation of a large black hole as a quantum amplitude, and note that during intermediate stages (e.g., after the Page time), the amplitude is a superposition of macroscopically distinct (and decohered) spacetimes, with the black hole itself in different positions on different branches. Small but semiclassical observers (who are themselves part of the quantum amplitude) that fall into the hole on one branch will miss it entirely on other branches and instead reach future infinity. This observation can reconcile the subjective experience of an infalling observer with unitarity. We also discuss implications for the nice slice formulation of the information problem, and to complementarity.