학술논문
Asymptotic expansions of oblate spheroidal wave functions and their characteristic numbers.
Document Type
Journal
Author
Müller, H. J. W. AMS Author Profile
Source
Subject
33 Special functions
33.28Lamé, Mathieu, spheroidal wave functions
33.28
Language
English
Abstract
The expansions and results in the paper reviewed above [MR0143965] are generalized to the oblate spheroidal wave functions which are, after a slight transformation, solutions of the differential equation $$ y''(x)+(2m+1)\cot x\cdot y'(x)+[\Lambda_0-m(m+1)-4h^2\sin^2x]y(x)=0. $$ Three pairs of asymptotic expansions are given in terms of trigonometrical functions and of generalized Laguerre functions. Linking and normalization factors are evaluated and the asymptotic eigenvalue expansions are calculated to two more terms than known previously. The various expansions enable one to express the eigenfunctions asymptotically over the whole range $0\leq x\leq\pi$.