118 research outputs found

    Uniform asymptotic expansions for the zeros of Bessel functions

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    Reformulated uniform asymptotic expansions are derived for ordinary differential equations having a large parameter and a simple turning point. These involve Airy functions, but not their derivatives, unlike traditional asymptotic expansions. From these, asymptotic expansions are derived for the zeros of Bessel functions that are valid for large positive values of the order, uniformly valid for all the zeros. The coefficients in the expansions are explicitly given elementary functions, and similar expansions are derived for the zeros of the derivatives of Bessel functions

    Conical: an extended module for computing a numerically satisfactory pair of solutions of the differential equation for conical functions

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    Conical functions appear in a large number of applications in physics and engineering. In this paper we describe an extension of our module CONICAL for the computation of conical functions. Specifically, the module includes now a routine for computing the function Rβˆ’12+iΟ„m(x){{\rm R}}^{m}_{-\frac{1}{2}+i\tau}(x), a real-valued numerically satisfactory companion of the function Pβˆ’12+iΟ„m(x){\rm P}^m_{-\tfrac12+i\tau}(x) for x>1x>1. In this way, a natural basis for solving Dirichlet problems bounded by conical domains is provided.Comment: To appear in Computer Physics Communication
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