Entanglement entropy and decoupling in the Universe
Entanglement entropy and decoupling in the Universe
复制标题
宇宙中的纠缠熵和解耦
DOI：
10.1103/physrevd.96.123518
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发表时间：
2017
影响因子：
5
通讯作者：
Masaki Yamada
中科院分区：
文献类型：
--
作者：
Yuichiro Nakai;Noburo Shiba;Masaki Yamada
在膨胀的宇宙中，当两个相互作用的场的相互作用速率小于哈勃膨胀速率时，它们就不再处于热接触状态。解耦后，两个子系统通常根据平衡态热力学分别处理，热力学熵给出了每个子系统中守恒的基准量。本文从耦合场的量子纠缠出发，讨论了对这一范式的修正。将热力学熵推广到纠缠熵。我们制定了一个微扰理论推导出纠缠熵和费曼规则的图解计算。对于具体的模型来说明我们的配方，相互作用的标量-标量系统，量子电动力学，汤川理论被认为是。我们计算了这些模型中的纠缠熵，并找到了对热力学熵的量子修正。在瞬时解耦的情况下，校正被揭示是重要的。
In the expanding universe, two interacting fields are no longer in thermal contact when the interaction rate becomes smaller than the Hubble expansion rate. After decoupling, two subsystems are usually treated separately in accordance with equilibrium thermodynamics and the thermodynamic entropy gives a fiducial quantity conserved in each subsystem. In this paper, we discuss a correction to this paradigm from quantum entanglement of two coupled fields. The thermodynamic entropy is generalized to the entanglement entropy. We formulate a perturbation theory to derive the entanglement entropy and present Feynman rules in diagrammatic calculations. For specific models to illustrate our formulation, an interacting scalar-scalar system, quantum electrodynamics, and the Yukawa theory are considered. We calculate the entanglement entropy in these models and find a quantum correction to the thermodynamic entropy. The correction is revealed to be important in circumstances of instantaneous decoupling.