The Four-Loop Dressing Phase of N=4 SYM

Understand

We compute the dilatation generator in the su(2) sector of planar N=4 super Yang-Mills theory at four-loops.

• We use the known world-sheet scattering matrix to constrain the structure of the generator.
• The remaining few coefficients can be computed directly from Feynman diagrams.
• This allows us to confirm previous conjectures for the leading contribution to the dressing phase which is proportional to zeta(3).