3 papers
math.CA2026
Old structures, a vanishing formula
K. Castillo, G. Gordillo-Núñez
We identify a normalization defect in a determinantal construction of fourth-order Hahn difference equations and compare its scalar equation with Foupouagnigni's 1998 elimination a…
math.CA2026
The manufacture of examples II: the "para-classical" orthogonal polynomials
K. Castillo, G. Gordillo-Núñez
Under the stated regularity assumptions, the full orthogonality functionals of the five finite para-families considered here are classical for the respective affine, quadratic, …
math.CA2026
The manufacture of examples: the -classical orthogonal polynomials
K. Castillo, G. Gordillo-Núñez
The big -Jacobi, Bannai-Ito, and -Meixner-Pollaczek polynomials have appeared in the mathematical physics literature through differential- or difference-reflection eige…