标题： 平坦空间极限的AdS耦合到热库 显示英文标题

标题： The Flat-Space Limit of AdS Coupled to a Bath

摘要： 我们解释如何对AdS与非引力浴耦合的膜模型取一个定义良好的平空间极限。在对应的边界共形场论（BCFT）中，这相当于一个三重缩放极限，其中边界自由度的数量和边界耦合都被取到无穷大，同时BCFT边界逐段趋近于光锥。我们说明这一过程如何作用于共形生成元上，作为一种Wigner-İnönü收缩，将全局BCFT对称代数缩减为平空间的全局对称代数。我们讨论了平空间对偶的两种自然的纠缠熵概念。这些概念的区别在于是否包含通过$\mathcal I^\pm$离开的模式，分别导致零和非平凡的Page曲线。通过对拓扑黑洞取平空间极限，我们证明在二维情况下Page时间保持有限。在$d > 2$中，Page时间在平极限下发散，因为AdS拓扑黑洞变为平空间Rindler视界。 显示英文摘要

摘要： We explain how to take a well-defined flat-space limit of brane models of AdS coupled to a non-gravitating bath. In the dual BCFT this amounts to a triple-scaling limit where both the number of boundary degrees of freedom and the boundary coupling are taken to infinity while the BCFT boundary piecewise approaches a lightcone. We show how this procedure acts on the conformal generators as a Wigner-\.In\"on\"u contraction, reducing the global BCFT symmetry algebra to the global symmetry algebra of flat space. We discuss two natural notions of entanglement entropy of the flat-space dual. These are distinguished by whether modes that have left through $\mathcal I^\pm$ are included or not and give rise to a vanishing and non-trivial Page curve, respectively. Taking the flat-space limit of topological black holes we show that the Page time remains finite in two-dimensions. In $d > 2$ the Page time diverges in the flat limit, since AdS topological black holes become flat-space Rindler horizons.