A uniform realization of the combinatorial R-matrix for column shape Kirillov–Reshetikhin crystals

Abstract

Kirillov–Reshetikhin (KR) crystals are colored directed graphs encoding the structure of certain finite-dimensional representations of affine Lie algebras. A tensor product of column shape Kirillov–Reshetikhin crystals has recently been realized in a uniform way, for all untwisted affine types, in terms of the so-called quantum alcove model. We enhance this model by using it to give a uniform realization of the corresponding combinatorial R-matrix, i.e., the unique affine crystal isomorphism permuting factors in a tensor product of column shape KR crystals. In other words, we are generalizing to all Lie types Schützenberger's sliding game (jeu de taquin) for Young tableaux, which realizes the combinatorial R-matrix in type A. Our construction is in terms of certain combinatorial moves, called quantum Yang–Baxter moves, which are explicitly described by reduction to the rank 2 root systems. We also show that the quantum alcove model does not depend on the choice of a sequence of alcoves joining the fundamental one to a translation of it.