Higher-order Casimir elements and hook partitions for quantum groups of types B, C and D

Abstract

The higher-order quantum Casimir elements, introduced by Zhang, Bracken, and Gould in the early 1990s, were conjectured to generate the centre of the Drinfeld-Jimbo quantum (super)groups. This was previously confirmed in the classical type A. In this paper we extend the result to the classical types B, C, D, with the additional inclusion of quantum Casimir elements arising from spin and half-spin representations in types B and D. We identify the Harish-Chandra images of these elements and reinterpret them uniformly in terms of irreducible characters associated with hook partitions. This yields explicit and minimal generating sets for the centres in all classical types, and provides new connections between higher-order quantum Casimir elements and hook partitions that exhibit a stability phenomenon.