A New Double-Scaling Limit of N=4 Super Yang-Mills Theory and PP-Wave Strings
C. Kristjansen, J. Plefka, G. W. Semenoff, M. Staudacher
TL;DR
The paper investigates a double-scaling limit of N=4 SYM that holographically corresponds to a pp-wave background in string theory. Using exact matrix-model techniques and combinatorial analysis, it shows that non-planar diagrams survive this limit and computes all-genus contributions to two- and three-point functions of chiral primaries, as well as the momentum-carrying operators that map to string excitations. It demonstrates non-planar mixing among these operators, requiring a redefinition that preserves orthogonality up to subleading order, and reveals non-planar corrections to their one-loop anomalous dimensions, signaling string-loop effects in the dual pp-wave description. The results provide a concrete realization of double-scaling dynamics in a holographic setting and establish precise scaling functions governing genus contributions in correlators.
Abstract
The metric of a spacetime with a parallel plane (pp)-wave can be obtained in a certain limit of the space AdS^5xS^5. According to the AdS/CFT correspondence, the holographic dual of superstring theory on that background should be the analogous limit of N=4 supersymmetric Yang-Mills theory. In this paper we shall show that, contrary to widespread expectation, non-planar diagrams survive this limiting procedure in the gauge theory. Using matrix model techniques as well as combinatorial reasoning it is demonstrated that a subset of diagrams of arbitrary genus survives and that a non-trivial double scaling limit may be defined. We exactly compute two- and three-point functions of chiral primaries in this limit. We also carefully study certain operators conjectured to correspond to string excitations on the pp-wave background. We find non-planar linear mixing of these proposed operators, requiring their redefinition. Finally, we show that the redefined operators receive non-planar corrections to the planar one-loop anomalous dimension.
