§1.13(viii) Eigenvalues and Eigenfunctions: Sturm-Liouville and Liouville forms
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►This is the Sturm-Liouvilleform of a second order differential equation, where ′ denotes .
Assuming that satisfies un-mixed boundary conditions of the form
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►In consequence they are doubly-periodic meromorphic functions of .
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►The prefixes , , , , , , , indicate the type of the polynomial form of the Lamé polynomial; compare the 3rd and 4th columns in Table 29.12.1.
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§29.12(ii) Algebraic Form
►With the substitution every Lamé polynomial in Table 29.12.1 can be written in the form
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►Figure 21.4.4: A real-valued scaled Riemann theta function: , , .
In this case, the quasi-periods are commensurable, resulting in a doubly-periodic configuration.
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►For asymptotic approximations of the solutions of Heun’s equation (31.2.1) when two singularities are close together, see Lay and Slavyanov (1999).
►For asymptotic approximations of the solutions of confluent forms of Heun’s equation in the neighborhood of irregular singularities, see Komarov et al. (1976), Ronveaux (1995, Parts B,C,D,E), Bogush and Otchik (1997), Slavyanov and Veshev (1997), and Lay et al. (1998).
►Confluent forms of Heun’s differential equation (31.2.1) arise when two or more of the regular singularities merge to form an irregular singularity.
…There are four standard forms, as follows:
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►This has regular singularities at and , and an irregular singularity of rank 1 at .
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