Orthogonal Polynomials in Analytical Method of Solving Differential Equations Describing Dynamics of Multilevel Systems

Asymptotics of multivariate orthogonal polynomials with hyperoctahedral symmetry

We present a formula describing the asymptotics of a class of multivariate orthogonal polynomials with hyperoctahedral symmetry as the degree tends to infinity. The polynomials under consideration are characterized by a factorized weight function satisfying certain analyticity assumptions. As an application, the large-degree asymptotics of the Koornwinder-Macdonald BC_N-type multivariate Askey-Wilson polynomials is determined.

Perturbations around the zeros of classical orthogonal polynomials

Starting from degree N solutions of a time dependent Schroedinger-like equation for classical orthogonal polynomials, a linear matrix equation describing perturbations around the N zeros of the polynomial is derived. The matrix has remarkable Diophantine properties. Its eigenvalues are independent of the zeros. The corresponding eigenvectors provide the representations of the lower degree (0,1,...,N-1) polynomials in terms of the zeros of the degree N polynomial. The results are valid universally for all the classical orthogonal polynomials, including the Askey scheme of hypergeometric orthogo…

带跳跃的高斯权正交多项式与离散潘勒韦方程

Orthogonal Polynomials for the Gaussian Weight with a Jump and Discrete Painlevé Equations

本文提出精细化的离散潘勒韦识别问题，强调超越表面类型描述动力学，并以带单跳跃高斯权正交多项式中的递推关系为例展示求解方法。

Exceptional Gegenbauer polynomials via isospectral deformation

We show a method to construct isospectral deformations of classical orthogonal polynomials. The construction is based on confluent Darboux transformations, and it allows to construct Sturm-Liouville problems with polynomial eigenfunctions that have an arbitrary number of continuous parameters. We propose to call these new orthogonal polynomial systems \emph{exceptional polynomials of the second kind}. We illustrate this construction by describing the class of exceptional Gegenbauer polynomials of the second kind.

On a novel class of polyanalytic Hermite polynomials

We carry out some algebraic and analytic properties of a new class of orthogonal polyanalytic polynomials, including their operational formulas, recurrence relations, generating functions, integral representations and different orthogonality identities. We establish their connection and rule in describing the $L^2$--spectral theory of some special second order differential operators of Laplacian type acting on the $L^2$--gaussian Hilbert space on the whole complex plane. We will also show their importance in the theory of the so-called rank--one automorphic functions on the complex plane. In f…

Multiplicity free induced representations and orthogonal polynomials

Let $(G,H)$ be a reductive spherical pair and $P\subset H$ a parabolic subgroup such that $(G,P)$ is spherical. The triples $(G,H,P)$ with this property are called multiplicity free systems and they are classified in this paper. Denote by $π^{H}_μ=\mathrm{ind}_{P}^{H}μ$ the Borel-Weil realization of the irreducible $H$-representation of highest weight $μ\in P^{+}_{H}$ and consider the induced representation $\mathrm{ind}_{P}^{G}χ_μ=\mathrm{ind}_{H}^{G}π^{H}_μ$, a multiplicity free induced representation. Some properties of the spectrum of the multiplicity free induced representations are discu…