A General Asymptotic Expansion Formula for Integrals Involving High-Order Orthogonal Polynomials

Abstract

A new method of evaluating overlap integrals involving orthogonal polynomials is proposed. The technique relies on purely algebraic manipulation of the associated recurrence coefficients. For a large class of polynomials and for sufficiently large orders, these coefficients can be written explicitly as Taylor series in terms of powers of $\epsilon=1/n$, where n is the polynomial order. Such decompositions are perfectly suited to the accurate numerical evaluation of integrals involving high-order polynomials. Examples include the numerical evaluation of integrals involving classical orthogonal polynomials such as Laguerre, Jacobi, and Gegenbauer.