标题： 从大$c$保角块中得到的类Vaidya时空中的新体锥奇点 显示英文标题

标题： New bulk cone singularities in Vaidya-like spacetimes from large $c$ conformal blocks

摘要： 在体中，当两点通过体中的零测地线分离时，边界两点函数中会出现体锥奇点，但在边界中不会出现。 在本工作中，我们描述了一类由产生黑洞的半径$r_+$标记的类似Vaidya时空中的新型体锥奇点。 我们在该时空族中发现，在$r_+=l$，即AdS长度处，因果结构出现了明显的转变。 特别是，存在一些体锥奇点，在$r_+>l$情况下不存在，但在$r_+<l$情况下会出现。 在存在此类奇点的$r_+<l$情况下，我们能够通过使用大$c$共形块在CFT$_2$计算中再现这些奇点。 显示英文摘要

摘要： Bulk cone singularities are singularities in boundary two-point functions at points separated by a null geodesic in the bulk, but not in the boundary. In this work, we describe a new type of bulk cone singularities in a family of Vaidya-like spacetimes that are labeled by the radius $r_+$ of the resulting black hole. We find a sharp transition in the causal structure within this family of spacetimes at $r_+=l$, the AdS length. In particular, there are bulk cone singularities that do not exist in the $r_+>l$ case, but appear for $r_+<l$. In the case of $r_+<l$ where such singularities exist, we are able to reproduce the singularities in a CFT$_2$ calculation using large $c$ conformal blocks.