Abstract
Let λ ∈ P+ be a level-zero dominant integral weight, and w the coset representative of minimal length for a coset in W/Wλ, where Wλ is the stabilizer of λ in a finite Weyl group W. In this paper, we give a module \( {\mathbbm{K}}_w^{-}\left(\uplambda \right) \) over the negative part of a quantum affine algebra whose graded character is identical to the specialization at t = ∞ of the nonsymmetric Macdonald polynomial Ewλ(q, t) multiplied by a certain explicit finite product of rational functions of q of the form (1 − q−r)−1 for a positive integer r. This module \( {\mathbbm{K}}_w^{-}\left(\uplambda \right) \) (called a level-zero van der Kallen module) is defined to be the quotient module of the level-zero Demazure module \( {V}_w^{-}\left(\uplambda \right) \) by the sum of the submodules \( {V}_z^{-}\left(\uplambda \right) \) for all those coset representatives z of minimal length for cosets in W/Wλ such that z > w in the Bruhat order < on W.
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Satoshi Naito is partially supported by JSPS Grant-in-Aid for Scientific Research (B) 16H03920.
Daisuke Sagaki is partially supported by JSPS Grant-in-Aid for Scientific Research (C) 15K04803.
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NAITO, S., SAGAKI, D. LEVEL-ZERO VAN DER KALLEN MODULES AND SPECIALIZATION OF NONSYMMETRIC MACDONALD POLYNOMIALS AT t = ∞. Transformation Groups 26, 1077–1111 (2021). https://doi.org/10.1007/s00031-020-09586-0
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DOI: https://doi.org/10.1007/s00031-020-09586-0