论文标题
在$ 1+1 $ D的因果钻石上，在SJ州的（非）Hadamard财产上
On the (Non)Hadamard Property of the SJ State in a $1+1$D Causal Diamond
论文作者
论文摘要
Sorkin-Johnston（SJ）状态是通用弯曲时空中标量场的候选物理真空状态。它具有吸引人的特征，即在任何全球双曲线时空上都在协变和唯一定义，如果有的话，通常反映了基础的对称性。 SJ状态的潜在缺点是它并不总是满足Hadamard条件。在这项工作中，我们研究了SJ状态在$ 1+1 $ D的因果钻石中的程度，Hadamard发现它不是Hadamard在边界上。然后，我们研究软化的SJ状态，这对原始状态进行了稍作修改，使其成为Hadamard。我们使用软化的SJ状态来研究因果集理论中纠缠熵的某些特殊特征是否可能与其非哈达姆性质有关。
The Sorkin-Johnston (SJ) state is a candidate physical vacuum state for a scalar field in a generic curved spacetime. It has the attractive feature that it is covariantly and uniquely defined in any globally hyperbolic spacetime, often reflecting the underlying symmetries if there are any. A potential drawback of the SJ state is that it does not always satisfy the Hadamard condition. In this work, we study the extent to which the SJ state in a $1+1$D causal diamond is Hadamard, finding that it is not Hadamard at the boundary. We then study the softened SJ state, which is a slight modification of the original state to make it Hadamard. We use the softened SJ state to investigate whether some peculiar features of entanglement entropy in causal set theory may be linked to its non-Hadamard nature.
