Four-point correlators of BPS operators in N=4 SYM at order g4 Original Research Article

We study the large N degeneracy in the structure of the four-point amplitudes of 12-BPS operators of arbitrary weight k in perturbative N=4 SYM theory. At one loop (order g2) this degeneracy manifests itself in a smaller number of independent conformal invariant functions describing the amplitude, compared to AdS5 supergravity results. To study this phenomenon at the two-loop level (order g4) we consider a particular N=2 hypermultiplet projection of the general N=4 amplitude. Using the formalism of N=2 harmonic superspace we then explicitly compute this four-point correlator at two loops and identify the corresponding conformal invariant functions.