标题： 量子场论中哈格展开的优点 显示英文标题

标题： VIRTUES OF THE HAAG EXPANSION IN QUANTUM FIELD THEORY

摘要： 我调查了哈格展开作为解决量子场论的一种技术。 在阐述渐近条件和哈格展开之后，我报告了将哈格展开应用于几种量子场论的结果，包括伽利略不变理论、有限温度下的物质（以BCS超导模型为例）、纳姆布-乔纳-拉辛奥模型和施温格模型。 最后，我展望了该方法进一步发展的前景。 显示英文摘要

摘要： I survey the use of the Haag expansion as a technique to solve quantum field theories. After an exposition of the asymptotic condition and the Haag expansion, I report the results of applying the Haag expansion to several quantum field theories, including galilean-invariant theories, matter at finite temperature (using the BCS model of superconductivity as an illustrative example), the Nambu--Jona-Lasinio model and the Schwinger model. I conclude with the outlook for further development of this method.