On Combinatorial Models for Affine Crystals

Abstract: The tableau model for Kirillov-Reshetikhin (KR) crystals, which are finite dimensional crystals corresponding to certain affine Lie algebras, is commonly used for its ease of crystal operator calculations. However, its simplicity makes quite complex the calculation of statistics such as: keys (used to express Demazure characters), the crystal energy function (an affine grading on tensor products of KR crystals), and the combinatorial R-matrix (an affine crystal isomorphism permuting factors in a tensor product of KR crystals). It has been shown that these calculations are much simpler with the added structure in the quantum alcove model for KR crystals. In this paper, we give an explicit description of the crystal isomorphism between the mentioned realizations of KR crystals in all classical Lie types.