Instanton contributions to anomalous dimensions in N = 4 SYM and the BMN limit

by Stefano Kovacs (AEI Potsdam)

Tuesday 2 Dec 2003, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

We discuss instanton contributions to the anomalous dimensions of gauge-invariant composite operators in the N=4 supersymmetric SU(N) Yang-Mills theory. We show how the study of two-point functions in the semiclassical approximation in the one-instanton sector allows to extract non-perturbative corrections to the scaling dimensions of composite operators. We consider scalar operators of dimension 2, 3, 4 and 5 and identify the sectors in which instanton corrections arise. The semiclassical analysis allows to derive non-renormalisation properties for a large class of operators. We present some examples for operators of small dimension and comment on the case of BMN operators. Some generalisations of the results and the implications on the structure of the dilation operator of the theory will be briefly discussed.