论文标题
页面时间之前的量子信息
On Quantum Information Before the Page Time
论文作者
论文摘要
尽管黑洞信息问题的最新进展表明，霍金辐射的熵遵循单一页面曲线，但在页面时间之前，鹰辐射的量子状态仍被视为纯粹的热力，其中不包含有关黑洞微观结构的信息。我们证明，在页面时间之前，鹰辐射中黑洞的量子状态有大量量子信息。通过计算黑洞蒸发的2D边界综合场理论（BCFT）模型中的量子保真度，我们证明，蒸发黑洞以外的观察者可以通过在蒸发过程中{avertit {Any}时间的鹰辐射来区分不同的黑洞。此外，我们的结果是普遍的，适用于一般的BCFT，包括大型中央电荷和理性BCFT。我们开发的用于计算保真度的技术通常适用于CFT中的激发状态。因此，我们能够表征2D共形场理论中热化的更一般方面。
While recent progress in the black hole information problem has shown that the entropy of Hawking radiation follows a unitary Page curve, the quantum state of Hawking radiation prior the Page time is still treated as purely thermal, containing no information about the microstructure of the black hole. We demonstrate that there is significant quantum information regarding the quantum state of the black hole in the Hawking radiation prior to the Page time. By computing of the quantum fidelity in a 2D boundary conformal field theory (BCFT) model of black hole evaporation, we demonstrate that an observer outside of an evaporating black hole may distinguish different black holes via measurements of the Hawking radiation at \textit{any} time during the evaporation process, albeit with an exponentially large number of measurements. Furthermore, our results are universal, applicable to general BCFTs including those with large central charge and rational BCFTs. The techniques we develop for computing the fidelity are more generally applicable to excited states in CFT. As such, we are able to characterize more general aspects of thermalization in 2D conformal field theory.
