Exact Superconformal and Yangian Symmetry of Scattering Amplitudes

Understand

We review recent progress in the understanding of symmetries for scattering amplitudes in N=4 superconformal Yang-Mills theory.

• It is summarized how the superficial breaking of superconformal symmetry by collinear anomalies and the renormalization process can be cured at tree and loop level.
• This is achieved by correcting the representation of the superconformal group on amplitudes.
• Moreover, we comment on the Yangian symmetry of scattering amplitudes and how it inherits these correction terms from the ordinary Lie algebra symmetry.