Correlation functions in N = 4 super Yang-Mills theory

by E. SOKATCHEV (LAPP, Annecy)

Thursday 4 Nov 1999, 14:00 → 16:30 Europe/Zurich

TH Auditorium (CERN)

We apply the harmonic superspace method to the study of correlation functions of gauge invariant composite operators in N=4 SYM theory. We prove a non-perturbative non-renormalisation theorem for the so-called 'extremal' four-point correlators, in agreement with recent results in AdS supergravity. This theorem holds for any Nc and not only in the large Nc limit. Further, using a manifestly N=2 supersymmetric Feynman graph technique we compute the correlator of four current-like operators at two loops and find a surprisingly simple result in terms of the well-known one-loop scalar box integral. It shows a characteristic logarithmic space-time singularity, once again in agreement with AdS supergravity as well as with instanton calculations.