Temperley–Lieb Crystals

Abstract Elements of Lusztig’s dual canonical bases are Schur-positive when evaluated on (generalized) Jacobi–Trudi matrices. This deep property was proved by Rhoades and Skandera, relying on a result of Haiman, and ultimately on the (proof of) Kazhdan–Lusztig conjecture. For a particularly tractable part of the dual canonical basis, called Temperley–Lieb immanants, we give a generalization of Littlewood–Richardson rule: we provide a combinatorial interpretation for the coefficient of a particular Schur function in the evaluation of a particular Temperley–Lieb immanant on a particular Jacobi–Trudi matrix. For this we introduce shuffle tableaux, and apply Stembridge’s axioms to show that certain graphs on shuffle tableaux are type $A$ Kashiwara crystals.