标题： 二维量子场论中的半经典方法：谱和有限尺寸效应 显示英文标题

标题： Semiclassical Methods in 2D QFT: Spectra and Finite-Size Effects

摘要： 我们回顾了通过半经典技术在二维量子场论分析中获得的一些近期结果，这些技术推广了七十年代Dashen、Hasllacher和Neveu以及Goldstone和Jackiw引入的方法。 这种方法最适合处理具有非线性相互作用势的量子场论，该势具有不同的简并极小值，在小耦合区域生成大质量的孤子激发。 在这些情况下，尽管所得结果基于小耦合假设，但它们仍然是非微扰的，因为进行半经典展开的孤子背景本身也是非微扰的。 我们将讨论半经典方法作为控制这些理论谱和有限尺寸效应的分析工具的有效性。 显示英文摘要

摘要： We review some recent results obtained in the analysis of two-dimensional quantum field theories by means of semiclassical techniques, which generalize methods introduced during the Seventies by Dashen, Hasllacher and Neveu and by Goldstone and Jackiw. The approach is best suited to deal with quantum field theories characterized by a non-linear interaction potential with different degenerate minima, that generates kink excitations of large mass in the small coupling regime. Under these circumstances, although the results obtained are based on a small coupling assumption, they are nevertheless non-perturbative, since the kink backgrounds around which the semiclassical expansion is performed are non-perturbative too. We will discuss the efficacy of the semiclassical method as a tool to control analytically spectrum and finite-size effects in these theories.