论文标题
量子反应的复杂时间途径
Complex time route to quantum backreaction
论文作者
论文摘要
我们考虑量子系统$ q $在与之相互作用的有效的经典自由度$ c $上的反应。基于标准路径积分形式主义的反应方程式给出了所谓的“输出”反应方程，该方程具有多种严重的病理。人们可以使用不同的反应处方，称为“ IN-IN”方法，该处方解决了所有“ In-On-Out”反应方程的问题。但是，通常以相当临时的方式调用此过程。在这里，我们通过利用沿复杂时间轮廓的量子进化的概念来提供“ IN-IN”方法的严格路径积分。事实证明，这种方法也可以用来以统一的方式研究“ In-In-In-In”和“ In-In-In-In-On-On-On-Out”反应方程。
We consider the backreaction of a quantum system $q$ on an effectively classical degree of freedom $C$ that is interacting with it. The backreaction equation based on the standard path integral formalism gives the so-called `in-out' backreaction equation, which has several serious pathologies. One can use a different backreaction prescription, referred to as the `in-in' approach, which resolves all the issues of `in-out' backreaction equation. However, this procedure is usually invoked in a rather ad hoc manner. Here we provide a rigorous path integral derivation of the `in-in' approach by exploiting the concept of quantum evolution along complex time contours. It turns out that, this approach can also be used to study both the `in-in' and `in-out' backreaction equations in a unified manner.
