Аннотация:
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.