We consider the unital associative algebra $mathcal{A}$ with two generators $mathcal{X}$, $mathcal{Z}$ obeying the defining relation $[mathcal{Z},mathcal{X}]=mathcal{Z}^2+Delta$. We construct irreducible tridiagonal representations of $mathcal{A}$. Depending on the value of the parameter $Delta$, these representations are associated to the Jacobi matrices of the para-Krawtchouk, continuous Hahn, Hahn or Jacobi polynomials.
Download