AI 中文总结
研究从过程矩阵组合论的谱中涌现因果序的机制，推导了与确定因果序兼容的过程的谱约束，发现在热力学极限下一般量子过程允许有确定因果序的优选分解，揭示仅从代数成分中涌现经典因果性的机制。
AI 中文摘要
在哈密顿系统中，唯一与基无关的量是谱。给定一个谱，量子组合论寻求到局部子系统的优选张量积分解，从而产生局域性。然而，因果序由哈密顿时间演化固定。相比之下，高阶量子理论允许更一般的过程，其不一定具有确定的全局因果序。在过程矩阵框架中，指定一个过程需要选择与每个主体的输入和输出希尔伯特空间相对应的子系统。基的变化会重新定义主体和相应的子系统分解，同时保持过程矩阵的谱不变。在此，我们研究因果性如何从这个谱中产生。首先，我们推导了与确定因果序兼容的过程的谱约束。其次，我们表明，在热力学极限下，一般的量子过程允许具有确定因果序的优选分解。这提出了一种仅从代数成分中涌现经典因果性的机制。
英文摘要
In Hamiltonian systems, the only basis-independent quantity is the spectrum. Given a spectrum, quantum mereology seeks preferred tensor-product decompositions into local subsystems, leading to the emergence of locality. Causal order, however, remains fixed by the Hamiltonian time evolution. In contrast, higher-order quantum theory permits more general processes that need not possess a definite global causal order. In the process-matrix framework, specifying a process requires a choice of subsystems corresponding to the input and output Hilbert spaces of each agent. A change of basis redefines both the agents and the corresponding decompositions into subsystems, while leaving the spectrum of the process matrix invariant. Here, we study how causality arises from this spectrum. First, we derive spectral constraints on processes compatible with definite causal order. Second, we show that, in the thermodynamic limit, generic quantum processes admit a preferred decomposition with a definite causal order. This suggests a mechanism for the emergence of classical causality only from algebraic ingredients.
