文摘
We study the polytope model for the affine type A Kirillov–Reshetikhin crystals and prove that the action of the affine Kashiwara operators can be described in a remarkably simple way. Moreover, we investigate the combinatorial R-matrix on a tensor product of polytopes and characterize the map explicitly on the highest weight elements. We further give a formula for the local energy function and provide an alternative proof for the perfectness. We determine for any dominant highest weight element \(\Lambda \) of level \(\ell \) the elements \(b_{\Lambda }, b^{\Lambda }\) involved in the definition of perfect crystals and give an explicit description of the ground-state path in the tensor product of polytopes.