论文标题
Sagex关于散射幅度的评论，第1章：振幅的现代基本原理
The SAGEX Review on Scattering Amplitudes, Chapter 1: Modern Fundamentals of Amplitudes
论文作者
论文摘要
本章介绍了散射幅度的基本要素。只有对量子场理论的基本理解，读者可以访问它。涵盖的主题包括：四维纺纱形形式主义和阳米尔散射幅度的颜色分解；阳米尔和重力振幅的软和共线极限的研究； BCFW递归关系和广义单位性，也是在$ \ mathcal {n} {=} {=}的超级宽度形式主义中； $ \ Mathcal {n} {=} 4 $ supersymmetric yang-mills的标准和隐藏对称性的概述，例如形成符号，二元组合和扬吉对称性；并简要介绍了Yang-Mills理论中受保护和不受保护的操作员的形式。还提供了几个示例和明确的计算。
This chapter introduces the foundational elements of scattering amplitudes. It is meant to be accessible to readers with only a basic understanding of quantum field theory. Topics covered include: the four-dimensional spinor-helicity formalism and the colour decomposition of Yang-Mills scattering amplitudes; the study of soft and collinear limits of Yang-Mills and gravity amplitudes; the BCFW recursion relation and generalised unitarity, also in the superamplitudes formalism of $\mathcal{N}{=}4$ supersymmetric Yang-Mills; an overview of standard and hidden symmetries of the $S$-matrix of $\mathcal{N}{=}4$ supersymmetric Yang-Mills, such as the conformal, dual conformal and Yangian symmetries; and a brief excursus on form factors of protected and non-protected operators in Yang-Mills theory. Several examples and explicit calculations are also provided.
