论文标题
重力电荷的异常，无效边界和黑洞熵
Anomalies in gravitational charge algebras of null boundaries and black hole entropy
论文作者
论文摘要
我们利用与固定无效的正常情况一致的最通用的边界条件，重新审视具有无效边界的重力理论的协变相形式主义。为了修复瓦尔德 - zoupas定义准电荷的固有的歧义，我们提出了一个基于全息推理的新原理，即通量是dirichlet形式的。这也产生了无效表面上棕色应力张量的类似物的表达。为开放子系统的Barnich-Troessaert支架定义电荷的代数，我们为中央（或更一般的Abelian）提供了一个通用公式，这些公式是根据重力作用中边界项的异常转换而出现的。这种异常是由固定了无效正常的框架引起的，我们在其与ADS/CFT中发生的全息韦伊尔异常之间绘制相似之处。作为这种形式主义的应用，我们分析了Haco，Hawking，Perry和Strominger考虑的近野体Virasoro对称性，并对通量和中央电荷进行系统的推导。将Cardy公式应用于结果，其熵是地平线的Bekenstein-Hawking熵的两倍。由扩展的希尔伯特太空构建的动机，我们用一对与分叉表面两侧的边缘模式相关的纠缠CFT来解释这一点。
We revisit the covariant phase space formalism applied to gravitational theories with null boundaries, utilizing the most general boundary conditions consistent with a fixed null normal. To fix the ambiguity inherent in the Wald-Zoupas definition of quasilocal charges, we propose a new principle, based on holographic reasoning, that the flux be of Dirichlet form. This also produces an expression for the analog of the Brown-York stress tensor on the null surface. Defining the algebra of charges using the Barnich-Troessaert bracket for open subsystems, we give a general formula for the central -- or more generally, abelian -- extensions that appear in terms of the anomalous transformation of the boundary term in the gravitational action. This anomaly arises from having fixed a frame for the null normal, and we draw parallels between it and the holographic Weyl anomaly that occurs in AdS/CFT. As an application of this formalism, we analyze the near-horizon Virasoro symmetry considered by Haco, Hawking, Perry, and Strominger, and perform a systematic derivation of the fluxes and central charges. Applying the Cardy formula to the result yields an entropy that is twice the Bekenstein-Hawking entropy of the horizon. Motivated by the extended Hilbert space construction, we interpret this in terms of a pair of entangled CFTs associated with edge modes on either side of the bifurcation surface.
