Three-point correlation functions in the $\mathfrak{sl}_3$ Toda theory I: Reflection coefficients
Baptiste Cerclé
TL;DR
The paper develops a probabilistic framework for $rak{sl}_3$ Toda CFTs by deriving reflection coefficients through a generalized Williams path decomposition in Weyl chambers. It builds a bridge between diffusion processes conditioned by generalized minima, Gaussian Free Fields, and Gaussian Multiplicative Chaos to obtain asymptotic expansions for Toda Vertex Operators and class-one Whittaker functions. The main contributions include a probabilistic formulation of Toda reflection coefficients, their expression in terms of GMC tails and Gamma-function factors, and a coherent scheme that parallels Liouville results while accommodating the richer Weyl-group structure of Toda theories. This advancement lays the groundwork for explicit probabilistic computations of three-point Toda correlators and reinforces the connection between stochastic processes in symmetric spaces and conformal field theory, with implications for the conformal bootstrap in higher-rank models.
Abstract
Toda Conformal Field Theories (CFTs) form a family of 2d CFTs indexed by semisimple and complex Lie algebras. They are natural generalizations of the Liouville CFT in that they enjoy an enhanced level of symmetry encoded by W-algebras. These theories can be rigorously defined using a probabilistic framework that involves the consideration of correlated Gaussian Multiplicative Chaos measures. This document provides a first step towards the computation of a class of three-point correlation functions, that generalize the celebrated DOZZ formula and whose expressions were predicted in the physics literature by Fateev-Litvinov, within the probabilistic framework associated to the $\mathfrak{sl}_3$ Toda CFT. Namely this first article of a two-parts series is dedicated to the probabilistic derivation of the reflection coefficients of general Toda CFTs, which are essential building blocks in the understanding of Toda correlation functions. Along the computations of these reflection coefficients a new path decomposition for diffusion processes in Euclidean spaces, based on a suitable notion of minimum and that generalizes the celebrated one-dimensional result of Williams, will be unveiled. As a byproduct we describe the joint tail expansion of correlated Gaussian Multiplicative Chaos measures together with an asymptotic expansion of class one Whittaker functions.
