论文标题
因果钻石合奏的熵
Entropy of causal diamond ensembles
论文作者
论文摘要
我们通过用固定的诱导度量和温度引入人工约克边界来定义重力因果钻石的规范合奏，并使用鞍点近似评估分区函数。对于零宇宙常数的爱因斯坦重力，没有确切的鞍座，但是地平线的一部分被边界包围的欧几里得钻石的一部分是在高温方向上的近似鞍形出现的，其中鞍形的地平线接近边界。这种高温分区函数对银行，德拉珀和法卡斯的最新计算提供了统计解释，其中因果钻石的熵从边界术语中回收了壳纤维化的作用。相比之下，具有正宇宙的正宇宙以及具有有限边界温度的精确鞍座的jackiw-teitelboim重力，但在这些情况下，由于鞍座由鞍座确定，而不是先验选择。
We define a canonical ensemble for a gravitational causal diamond by introducing an artificial York boundary inside the diamond with a fixed induced metric and temperature, and evaluate the partition function using a saddle point approximation. For Einstein gravity with zero cosmological constant there is no exact saddle with a horizon, however the portion of the Euclidean diamond enclosed by the boundary arises as an approximate saddle in the high-temperature regime, in which the saddle horizon approaches the boundary. This high-temperature partition function provides a statistical interpretation of the recent calculation of Banks, Draper and Farkas, in which the entropy of causal diamonds is recovered from a boundary term in the on-shell Euclidean action. In contrast, with a positive cosmological constant, as well as in Jackiw-Teitelboim gravity with or without a cosmological constant, an exact saddle exists with a finite boundary temperature, but in these cases the causal diamond is determined by the saddle rather than being selected a priori.
