热场动力学中的切割图方法及热格林函数的虚部

在热场动力学的框架下,依据有限温度下的切割定理提出了一套直观的费曼图切割方法及其相应的费曼规则,从而给出了一条计算热格林函数应部的方便途径.作为应用的例子我们分别讨论了二点、三点和四点格林函数的虚部.

Cutting Rules and Imaginary Parts of Thermal Green Functions in Thermofield Dynamics

Under the Thermofield Dynamics, according to the cutting theorem at finite temperature a set of systematic explicit cutting rules to the Feynman diagrams and the relative Feynman rules are proposed, which can be used as an easy approach to calculate the imaginary parts of the thermal Green functions. We applied it to study the imaginary parts of two-point,three-point and four-point Green functions as examples.