We describe how the
Kashiwara involution ∗ on crystals of affine type A is encoded by the combinatorics
of aperiodic multisegments. This affords an elementary proof that ∗ coincides
with the Zelevinsky involution τ on the set of simple modules for the affine
Hecke algebras. We then give efficient procedures for computing ∗ and τ.
Remarkably, these procedures do not use the underlying crystal structure. They
also allow one to explicitly match to each other the Ginzburg and Ariki
parametrizations of simple modules associated to affine and cyclotomic Hecke
algebras, respectively.
Université du Littoral —Côte
d’Opale
Laboratoire de mathématiques pures et appliquées Joseph
Liouville
Centre Universitaire de la Mi-Voix
B.P. 699
62228 Calais
France