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arXiv 0710.5652hep-th
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一般态量子场论中格林函数的结构

The structure of Green functions in quantum field theory with a general state

Christian Brouder

摘要:

在量子场论中,格林函数通常被计算为真空上场的时间序乘积的期望值。在某些情况下,特别是在退化系统中,需要一般状态的期望值。相应的格林函数本质上比真空中的格林函数更复杂,因为它们不能用标准的费曼图来表示。在这里,提出了一种方法来确定这些格林函数的结构,并推导出非微扰方程。其主要思想是将描述相关性的累积量转化为相互作用项。

英文摘要:

In quantum field theory, the Green function is usually calculated as the expectation value of the time-ordered product of fields over the vacuum. In some cases, especially in degenerate systems, expectation values over general states are required. The corresponding Green functions are essentially more complex than in the vacuum, because they cannot be written in terms of standard Feynman diagrams. Here, a method is proposed to determine the structure of these Green functions and to derive nonperturbative equations for them. The main idea is to transform the cumulants describing correlations into interaction terms.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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