论文标题
在边界附近的观察者的物理方案，以获取量子重力中的批量信息
A physical protocol for observers near the boundary to obtain bulk information in quantum gravity
论文作者
论文摘要
我们考虑了一组居住在全球广告边界附近的观察者，并且只能以简单的低能单位行动起作用，并以较小的时间间隔进行测量。观察者不允许离开近边界区域。我们描述了一种物理方案，尽管如此，这些观察者仍然可以获得有关批量状态的详细信息。该协议利用了批量激发对度量的主要引力反应，还依赖于真空的纠缠结构。对于低能状态，我们展示了近似观察者如何使用该协议来完全识别散装状态。我们解释了为什么协议在没有重力的理论中完全失败，包括非严格规格理论。这为以下声称提供了扰动证据，即全息图（关于散装的信息也可以在边界附近也可用的事实）在低能的重力理论中已经可见。
We consider a set of observers who live near the boundary of global AdS, and are allowed to act only with simple low-energy unitaries and make measurements in a small interval of time. The observers are not allowed to leave the near-boundary region. We describe a physical protocol that nevertheless allows these observers to obtain detailed information about the bulk state. This protocol utilizes the leading gravitational back-reaction of a bulk excitation on the metric, and also relies on the entanglement-structure of the vacuum. For low-energy states, we show how the near-boundary observers can use this protocol to completely identify the bulk state. We explain why the protocol fails completely in theories without gravity, including non-gravitational gauge theories. This provides perturbative evidence for the claim that one of the signatures of holography -- the fact that information about the bulk is also available near the boundary -- is already visible in the low-energy theory of gravity.
