High Energy Theory Seminar

Over the past few years, a remarkable duality between planar scattering amplitudes and null polygonal Wilson Loops has emerged in maximally supersymmetric Yang-Mills theory. The duality is now known to hold for arbitrary external helicities and to all orders in the 't Hooft coupling. I will review our understanding of this duality from the point of view of the twistor formulation of the theory. At tree level, the scattering amplitudes are powerfully constrained by an infinite dimensional Yangian symmetry. I will also argue that, properly understood, a large part of this symmetry extends to loop amplitudes.