4 problems

Let $T(q)$ be the CKP Darboux transformation associated with a solution $q$, let $g\in Sp_{\infty}$, and write the corresponding tau function as … Let…

Let $P_n$ be a sequence of monic polynomials obtained as eigenpolynomials of a linear differential operator solving the classical Bochner–Krall problem. Let $T$ and $T^{-1}$ denote…

Gómez-Ullate–Kamran–Milson conjecture. Every exceptional orthogonal polynomial system of codimension $m$ can be obtained by applying a sequence of at most $m$ Darboux transformatio…

m-step Darboux conjecture. Every $\mathrm{X}_m$ orthogonal polynomial system for any codimension $m$ can be obtained by applying a sequence of at most $m$ Darboux transformations t…