Non-Hermitian Orthogonal Polynomials on a Trefoil

Monic Non-commutative Orthogonal Polynomials

For a measure μ on R, the situation is more subtle. One can always orthogonalize the subspaces of polynomials of different total degree (so that one gets a family of pseudo-orthogonal polynomials). The most common approach is to work directly with these subspaces, without producing individual orthogonal polynomials; see, for example [DX01]. One can also further orthogonalize the polynomials of ...

On Orthogonal Polynomials Spanning a Non-standard Flag

We survey some recent developments in the theory of orthogonal polynomials defined by differential equations. The key finding is that there exist orthogonal polynomials defined by 2nd order differential equations that fall outside the classical families of Jacobi, Laguerre, and Hermite polynomials. Unlike the classical families, these new examples, called exceptional orthogonal polynomials, fea...

On Orthogonal Matrix Polynomials

In this paper we deal with orthogonal matrix polynomials. First of all, we establish some basic notations and results we need later. A matrix polynomial P is a matrix whose entries are polynomials, or, equivalently, a combination P(t) = A 0 +A 1 t+ +A n t n , where A 0 ; ; A n are numerical matrices (the size of all the matrices which appear in this paper is N N). A positive deenite matrix of m...

Laplace and Segal-bargmann Transforms on Hermitian Symmetric Spaces and Orthogonal Polynomials

On orthogonal polynomials for certain non-definite linear functionals

We consider the non-definite linear functionals Ln[f ] = ∫ IR w(x)f (n)(x) dx and prove the nonexistence of orthogonal polynomials, with all zeros real, in several cases. The proofs are based on the connection with moment preserving spline approximation.