RUS  ENG
Full version
JOURNALS // Symmetry, Integrability and Geometry: Methods and Applications // Archive

SIGMA, 2023 Volume 19, 090, 19 pp. (Mi sigma1985)

Para-Bannai–Ito Polynomials

Jonathan Pelletiera, Luc Vinetab, Alexei Zhedanovc

a Centre de Recherches Mathématiques, Université de Montréal, P.O. Box 6128, Centre-ville Station, Montréal (Québec), H3C 3J7, Canada
b IVADO, Montréal (Québec), H2S 3H1, Canada
c School of Mathematics, Renmin University of China, Beijing 100872, P.R. China

Abstract: New bispectral polynomials orthogonal on a Bannai–Ito bi-lattice (uniform quadri-lattice) are obtained from an unconventional truncation of the untruncated Bannai–Ito and complementary Bannai–Ito polynomials. A complete characterization of the resulting para-Bannai–Ito polynomials is provided, including a three term recurrence relation, a Dunkl-difference equation, an explicit expression in terms of hypergeometric series and an orthogonality relation. They are also derived as a $q\to -1$ limit of the $q$-para-Racah polynomials. A connection to the dual $-1$ Hahn polynomials is also established.

Keywords: para-orthogonal polynomials, Bannai–Ito polynomials, Dunkl operators.

MSC: 33C45

Received: June 10, 2023; in final form October 28, 2023; Published online November 10, 2023

Language: English

DOI: 10.3842/SIGMA.2023.090


ArXiv: 2209.10725


© Steklov Math. Inst. of RAS, 2025