WKB approximation, crystals and combinatorics of Young tableaux
Xiaomeng Xu
TL;DR
This work establishes a deep bridge between the analytic Stokes phenomena of the quantum confluent hypergeometric equation and the combinatorics of Young tableaux via WKB methods. By evaluating Stokes/connection data at caterpillar points and in GT bases, it derives a transcendental realization of the gl_n-crystal structure on semistandard Young tableaux and recovers the Robinson–Schensted correspondence, the Littlewood–Richardson rule, and Schützenberger involutions as WKB phenomena. It further connects these to quantum groups, providing explicit formulas for quantum Stokes/connection matrices and a coproduct formalism that mirrors crystal tensor products. The framework unifies analytic, algebraic, and combinatorial perspectives, offering new tools to study representation theory through isomonodromic and WKB techniques. It also illuminates how wall-crossing phenomena encode combinatorial symmetries in tableau theory and crystal operators.
Abstract
In this paper, we show how various combinatorial algorithms of Young tableaux naturally arise from the WKB approximation of the connection matrix of quantum confluent hypergeometric equation, including the Robinson-Schensted algorithm, the Littlewood-Richardson rule and the Schützenberger involution.
