Orthogonal zero interpolants (OZI) are polynomials which interpolate the “zero-function” at a finite number of pre-assigned nodes and satisfy orthogonality condition. OZI’s can be constructed by the 3-term recurrence relation. These interpolants are found useful in the solution of constrained approximation problems and in the structure of Gauss-type quadrature rules. We present some theoretical...

In this paper, a special technique is studied by using the orthogonal Chebyshev polynomials to get approximate solutions for singular and hyper-singular integral equations of the first kind. A singular integral equation is converted to a system of algebraic equations based on using special properties of Chebyshev series. The error bounds are also stated for the regular part of approximate solut...

This paper discusses operators lowering or raising the degree but preserving the parameters of special orthogonal polynomials. Results for onevariable classical (q-)orthogonal polynomials are surveyed. For Jacobi polynomials associated with root system BC2 a new pair of lowering and raising operators is obtained.

Orthogonal polynomials have very useful properties in the mathematical problems, so recent years have seen a great deal in the field of approximation theory using orthogonal polynomials. In this paper, we characterize a sequence of the generalized Chebyshev-type polynomials of the first kind { T (M,N) n (x) } n∈N∪{0} , which are orthogonal with respect to the measure √ 1−x2 π dx + Mδ−1 + Nδ1, w...

We report on the recent development on the general theory of orthogonal polynomials in several variables, in which results parallel to the theory of orthogonal polynomials in one variable are established using a vectormatrix notation.

A method to locate the zeros of orthogonal polynomials with respect to non-standard inner products is discussed and applied to Sobolev orthogonal polyno-mials and polynomials satisfying higher-order recurrence relations.

Laurent polynomials related to the Hahn-Exton q-Bessel function, which are qanalogues of the Lommel polynomials, have been introduced by Koelink and Swarttouw. The explicit strong moment functional with respect to which the Laurent q-Lommel polynomials are orthogonal is given. The strong moment functional gives rise to two positive definite moment functionals. For the corresponding sets of orth...

A positive quadrature formula with n nodes which is exact for polynomials of degree In — r — 1, 0 < r < « , is based on the zeros of certain quasi-orthogonal polynomials of degree n . We show that the quasi-orthogonal polynomials that lead to the positive quadrature formulae can all be expressed as characteristic polynomials of a symmetric tridiagonal matrix with positive subdiagonal entries. A...

Techniques from “old style” orthogonal polynomials have turned out to be useful in establishing universality limits for fairly general measures. We survey some of these. Orthogonal Polynomials, RandomMatrices, Unitary Ensembles, Correlation Functions, Christo¤el functions. 15B52, 60B20, 60F99, 42C05, 33C50