Monodromic vs geodesic computation of Virasoro classical conformal blocks
K. B. Alkalaev, V. A. Belavin
TL;DR
This work computes the 5-point Virasoro classical conformal block in a heavy–light–superlight setup using the monodromy method and demonstrates its exact match with a bulk geodesic computation in AdS$_3$/CFT$_2$ up to third order in the superlight expansion. The authors develop a perturbative scheme around a known 4-point seed to solve the monodromic equations and compare the resulting accessory parameters with bulk angular momenta and geodesic actions, establishing a common root between boundary and bulk descriptions. They provide explicit formulas for the block and the bulk action up to third order, show how the two approaches are related by a precise mapping between boundary punctures and bulk attachment points, and discuss the implications for the AdS/CFT correspondence and Liouville theory’s role in encoding the semiclassical dynamics. The results reinforce a strong, dual description of Liouville-type dynamics in the semiclassical regime and clarify how multi-particle geodesic configurations encode boundary conformal data in the heavy-light limit.
Abstract
We compute 5-point classical conformal blocks with two heavy, two light, and one superlight operator using the monodromy approach up to third order in the superlight expansion. By virtue of the AdS/CFT correspondence we show the equivalence of the resulting expressions to those obtained in the bulk computation for the corresponding geodesic configuration.
