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arXiv · 2203.13012

The SAGEX Review on Scattering Amplitudes, Chapter 1: Modern Fundamentals of Amplitudes

Andreas Brandhuber·Jan Plefka·Gabriele Travaglini
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Abstract

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.

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Andreas Brandhuber, Jan Plefka, Gabriele Travaglini. 2022-03-24. The SAGEX Review on Scattering Amplitudes, Chapter 1: Modern Fundamentals of Amplitudes. https://arxiv.org/abs/2203.13012

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