标题： 黑洞及其他物体导致量子叠加退相干的局域描述 显示英文标题

标题： Local Description of Decoherence of Quantum Superpositions by Black Holes and Other Bodies

摘要： 先前的工作表明，如果实验者爱丽丝放置一个大质量或带电的物体处于量子空间叠加态中，那么黑洞（更一般地说，任何克尔 horizon）的存在最终会使得这种叠加态失去相干性 [arXiv:2205.06279, arXiv:2301.00026, arXiv:2311.11461]。 这种去相干现象被归因于通过 horizon 辐射出的软光子/引力子，这表明时空的整体结构对于描述这种去相干现象是至关重要的。 在这篇论文中，我们展示了可以通过爱丽丝实验室内的量子场局域两点函数来替代性地描述这种去相干现象，而无需直接参考 horizon。 从这个角度来看，在黑洞存在的情况下爱丽丝叠加态的去相干来源于爱丽丝实验室中存在的极低频的霍金量子。 我们明确计算了施瓦西时空在乌尔霍真空中的去相干现象，从局域的观点出发。 然后我们利用这个观点阐明：(i) 在布劳威尔和哈特尔-霍金真空中，施瓦西时空中的去相干效应差异；(ii) 与充满热浴的闵可夫斯基时空相比，施瓦西时空中的去相干效应差异；(iii) 静态恒星时空尽管外部真空态在许多方面类似于黑洞周围的布劳威尔真空，但缺乏去相干效应；以及 (iv) 模拟黑洞去相干效应所需的物质体自由度要求。 显示英文摘要

摘要： It was previously shown that if an experimenter, Alice, puts a massive or charged body in a quantum spatial superposition, then the presence of a black hole (or more generally any Killing horizon) will eventually decohere the superposition [arXiv:2205.06279, arXiv:2301.00026, arXiv:2311.11461]. This decoherence was identified as resulting from the radiation of soft photons/gravitons through the horizon, thus suggesting that the global structure of the spacetime is essential for describing the decoherence. In this paper, we show that the decoherence can alternatively be described in terms of the local two-point function of the quantum field within Alice's lab, without any direct reference to the horizon. From this point of view, the decoherence of Alice's superposition in the presence of a black hole arises from the extremely low frequency Hawking quanta present in Alice's lab. We explicitly calculate the decoherence occurring in Schwarzschild spacetime in the Unruh vacuum from the local viewpoint. We then use this viewpoint to elucidate (i) the differences in decoherence effects that would occur in Schwarzschild spacetime in the Boulware and Hartle-Hawking vacua; (ii) the difference in decoherence effects that would occur in Minkowski spacetime filled with a thermal bath as compared with Schwarzschild spacetime; (iii) the lack of decoherence in the spacetime of a static star even though the vacuum state outside the star is similar in many respects to the Boulware vacuum around a black hole; and (iv) the requirements on the degrees of freedom of a material body needed to produce a decoherence effect that mimics that of a black hole.