论文标题
插入系统的实时图技术
Real-time diagram technique for instantonic systems
论文作者
论文摘要
Schwinger-keldysh图技术通常参与实时IN相关函数的计算。在热态的情况下，可以在分析上继续进行假想的时间Matsubara相关功能与实际时间。然而，并非所有实时相关函数通常都可以通过这种过程获得。此外，数值分析延续是一个错误的问题。因此，即使在热状态下，也可能需要施温格 - 克尔迪什形式主义。如果系统的潜力允许变性最小值，则激发效果会进入游戏，因此也应该在包括假想时间翻译不变性相对应的激体模量空间（包括一个）上集成。但是，Schwinger-keldysh关闭了时间轮廓明确破坏了这种不变性。我们认为，必须恢复这种不变性，并显示如何完成。之后，我们构建了Schwinger-keldysh图技术的扩展，以激发系统，并在第一个几点相关函数的示例中进行演示。
The Schwinger-Keldysh diagram technique is usually involved in the calculation of real-time in-in correlation functions. In the case of a thermal state, one can analytically continue imaginary-time Matsubara correlation functions to real times. Nevertheless, not all real-time correlation functions usually can be obtained by such procedure. Moreover, numerical analytic continuation is an ill-posed problem. Thus, even in the case of a thermal state one may need for the Schwinger-Keldysh formalism. If the potential of a system admits degenerate minima, instantonic effects enter the game, so one should also integrate over the instantonic moduli space, including the one, corresponding to the imaginary time translational invariance. However, the Schwinger-Keldysh closed time contour explicitly breaks such invariance. We argue, that this invariance must be recovered, and show, how it can be done. After that, we construct an extension of the Schwinger-Keldysh diagram technique to instantonic systems and demonstrate it on the example of the first few-point correlation functions.
