The role of leading twist operators in the Regge and Lorentzian OPE limits
Miguel S. Costa, James Drummond, Vasco Goncalves, Joao Penedones
TL;DR
This work analyzes the weak-coupling Regge and Lorentzian OPE limits of the stress-tensor four-point function in $\mathcal{N}=4$ SYM, showing that both limits are governed by leading-twist operators. By leveraging the known three-loop correlator and the pomeron residue at next-to-leading order, the authors derive leading-log behaviors at arbitrary loop order and the next-to-leading logs up to four loops, establishing consistency with conformal Regge theory. They relate Regge data to OPE coefficients via an all-loop Regge-OPE dictionary, enabling predictions for the behavior of OPE coefficients near $J=1$ and providing nontrivial cross-checks of the approach through maximal transcendentality. The results constrain the higher-loop structure of the four-point function and offer inputs for a perturbative bootstrap program in planar $\mathcal{N}=4$ SYM.
Abstract
We study two kinematical limits, the Regge limit and the Lorentzian OPE limit, of the four-point function of the stress-tensor multiplet in Super Yang-Mills at weak coupling. We explain how both kinematical limits are controlled by the leading twist operators. We use the known expression of the four-point function up to three loops, to extract the pomeron residue at next-to-leading order. Using this data and the known form of pomeron spin up to next-to-leading order, we predict the behaviour of the four-point function in the Regge limit at higher loops. Specifically, we determine the leading log behaviour at any loop order and the next-to-leading log at four loops. Finally, we check the consistency of our results with conformal Regge theory. This leads us to predict the behaviour around $J=1$ of the OPE coefficient of the spin $J$ leading twist operator in the OPE of two chiral primary operators.
