Spectral Parameters for Scattering Amplitudes in N=4 Super Yang-Mills Theory

Understand

Planar N=4 Super Yang-Mills theory appears to be a quantum integrable four-dimensional conformal theory.

• This has been used to find equations believed to describe its exact spectrum of anomalous dimensions.
• Integrability seemingly also extends to the planar space-time scattering amplitudes of the N=4 model, which show strong signs of Yangian invariance.
• However, in contradistinction to the spectral problem, this has not yet led to equations determining the exact amplitudes.