Yangian Symmetry in N=4 super Yang-Mills
  In this paper we review recent results on symmetries in N=4 super Yang-Mills theory. Symmetries are of invaluable help in studying and constraining the scattering amplitudes, and there has been a lot of progress in recent years concerning this topic. It has been realised that the ordinary superconformal symmetry is not the full symmetry of this theory. There is indeed a dual superconformal symmetry, and together they form a Yangian structure, pointing to the underlying integrability of the theory. Here we give an overview of the Yangian algebra and of its action on the scattering amplitudes, at tree and loop level. This article is an invited review for the Focus Issue "Gauge/String Duality 2011" of Advances in High Energy Physics. 
L. Ferro
hep-th