Exacting N=4 Superconformal Symmetry

Understand

Tree level scattering amplitudes in N=4 super Yang-Mills theory are almost, but not exactly invariant under the free action of the N=4 superconformal algebra.

• What causes the non-invariance is the holomorphic anomaly at poles where external particles become collinear.
• In this paper we propose a deformation of the free superconformal representation by contributions which change the number of external legs.
• This modified classical representation not only makes tree amplitudes fully invariant, but it also leads to additional constraints from symmetry alone mediating between hitherto unrelated amplitudes.