Digital Library of Mathematical Functions
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28 Mathieu Functions and Hill’s EquationModified Mathieu Functions

§28.23 Expansions in Series of Bessel Functions

We use the following notations:

compare §10.2(ii). For the coefficients c^{{\nu}}_{{n}}(q) see §28.14. For A_{n}^{m}(q) and B_{n}^{m}(q) see §28.4.

valid for all z when j=1, and for \realpart{z}>0 and |\mathop{\cosh\/}\nolimits z|>1 when j=2,3,4.

valid for all z when j=1, and for \realpart{z}>0 and |\mathop{\sinh\/}\nolimits z|>1 when j=2,3,4.

In the case when \nu is an integer

When j=1, each of the series (28.23.6)–(28.23.13) converges for all z. When j=2,3,4 the series in the even-numbered equations converge for \realpart{z}>0 and |\mathop{\cosh\/}\nolimits z|>1, and the series in the odd-numbered equations converge for \realpart{z}>0 and |\mathop{\sinh\/}\nolimits z|>1.

For proofs and generalizations, see Meixner and Schäfke (1954, §§2.62 and 2.64).