The algebra of dual -1 Hahn polynomials and the Clebsch-Gordan problem of sl_{-1}(2)

Abstract

The algebra H of the dual -1 Hahn polynomials is derived and shown to arise in the Clebsch-Gordan problem of sl_{-1}(2). The dual -1 Hahn polynomials are the bispectral polynomials of a discrete argument obtained from a q-> -1 limit of the dual q-Hahn polynomials. The Hopf algebra sl_{-1}(2) has four generators including an involution, it is also a q-> -1 limit of the quantum algebra sl_{q}(2) and furthermore, the dynamical algebra of the parabose oscillator. The algebra H, a two-parameter generalization of u(2) with an involution as additional generator, is first derived from the recurrence relation of the -1 Hahn polynomials. It is then shown that H can be realized in terms of the generators of two added sl_{-1}(2) algebras, so that the Clebsch-Gordan coefficients of sl_{-1}(2) are dual -1 Hahn polynomials. An irreducible representation of H involving five-diagonal matrices and connected to the difference equation of the dual -1 Hahn polynomials is constructed.

15 pages, Some minor changes from version #1

References in corpus (5)

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Cited by in corpus (5)

• Bispectrality of the Complementary Bannai-Ito Polynomials
• The Bannai-Ito algebra and some applications
• A finite oscillator model with equidistant position spectrum based on an extension of $\mathfrak{su}(2)$
• Superintegrability and the dual $-1$ Hahn algebra in superconformal quantum mechanics
• A Howe correspondence for the algebra of the $\mathfrak{osp}(1|2)$ Clebsch-Gordan coefficients