论文标题
费米问题和马格努斯扩张中的因果关系
Causality in the Fermi Problem and the Magnus expansion
论文作者
论文摘要
1932年，费米提出了一个两种原子模型，用于确定量子力学是否与因果关系一致，并得出结论。在1960年代后期，Shirokov和其他人发现Fermi的近似值可能不是合理的，并且在纠正时，费米的模型显示出非灾难的行为。我们表明，如果不是时间依赖性的扰动理论，则使用Magnus膨胀来近似时间进化运算符，因此确实随之而来。
In 1932, Fermi presented a two-atom model for determining whether quantum mechanics is consistent with causality, and concluded that indeed it is. In the late 1960's, Shirokov and others found that Fermi's approximations may not have been sound, and when corrected, Fermi's model shows non-causal behavior. We show that if instead of time-dependent perturbation theory, the Magnus expansion is used to approximate the time-evolution operator, causality does follow.
