论文标题
可接受的因果结构和相关性
Admissible Causal Structures and Correlations
论文作者
论文摘要
众所周知，如果人们假设量子理论在局部持有，那么具有无限因果关系和环状因果结构的过程将变得可行。在这里，我们研究了局部量子理论对因果结构和相关性的定性局限性。首先，我们发现一个必要的图理论标准 - “婚姻中的兄弟姐妹”的财产 - 有因果结构是可以接受的：只有这种因果结构才能实现与局部量子理论一致的实现。我们猜想此属性还足够。这种猜想是由量子因果模型的明确构造的动机，并得到数值计算的支持。我们表明，这些因果模型在受限的环境中确实是一致的。对于另一个人来说，我们确定了两组因果结构，在经典的情况下，它们分别引起因果关系和非因果关系。
It is well-known that if one assumes quantum theory to hold locally, then processes with indefinite causal order and cyclic causal structures become feasible. Here, we study qualitative limitations on causal structures and correlations imposed by local quantum theory. For one, we find a necessary graph theoretic criterion--the "siblings-on-cycles" property--for a causal structure to be admissible: Only such causal structures admit a realization consistent with local quantum theory. We conjecture that this property is moreover sufficient. This conjecture is motivated by an explicit construction of quantum causal models, and supported by numerical calculations. We show that these causal models, in a restricted setting, are indeed consistent. For another, we identify two sets of causal structures that, in the classical-deterministic case, give rise to causal and non-causal correlations respectively.
