On-shell methods for off-shell quantities in N=4 Super Yang-Mills: from scattering amplitudes to form factors and the dilatation operator

Understand

Planar maximally supersymmetric Yang-Mills theory (N=4 SYM) is a special quantum field theory.

• A few of its remarkable features are conformal symmetry at the quantum level, evidence of integrability and, moreover, it is a prime example of the AdS/CFT duality.
• Triggered by Witten's twistor string theory, the past 15 years have witnessed enormous progress in reformulating this theory to make as many of these special features manifest, from the choice of convenient variables to recursion relations that allowed new mathematical structures to appear, like the Grassmannian.
• These methods are collectively referred to as on-shell methods.