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TW 574

Karl Deckers and Adhemar Bultheel
Rational interpolation and quadrature on the interval and on the unit circle

Abstract

Given a bounded Borel measure μ on the interval [-1,1], we provide convergence results in L²(μ)-norm to a function f of its sequence of rational interpolating functions at the nodes of rational Gauss-type quadrature formulas associated with the measure μ. As an application, we construct rational interpolatory quadrature formulas for complex bounded measures σ on the interval, and give conditions to ensure the convergence of these quadrature rules. Further, an upper bound for the error on the nth approximation and an estimate for the rate of convergence is provided for these quadrature rules. Addidtionally, we briefly give similar results for certain rational interpolatory quadrature formulas associated with measures supported on the complex unit circle.

report.pdf (545K) / mailto: K. Deckers