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33 Coulomb FunctionsVariables \rho,\eta

§33.13 Complex Variable and Parameters

The functions \mathop{F_{{\ell}}\/}\nolimits\!\left(\eta,\rho\right), \mathop{G_{{\ell}}\/}\nolimits\!\left(\eta,\rho\right), and \mathop{{H^{{\pm}}_{{\ell}}}\/}\nolimits\!\left(\eta,\rho\right) may be extended to noninteger values of \ell by generalizing (2\ell+1)!=\mathop{\Gamma\/}\nolimits\!\left(2\ell+2\right), and supplementing (33.6.5) by a formula derived from (33.2.8) with \mathop{U\/}\nolimits\!\left(a,b,z\right) expanded via (13.2.42).

These functions may also be continued analytically to complex values of \rho, \eta, and \ell. The quantities \mathop{C_{{\ell}}\/}\nolimits\!\left(\eta\right), \mathop{{\sigma_{{\ell}}}\/}\nolimits\!\left(\eta\right), and R_{\ell}, given by (33.2.6), (33.2.10), and (33.4.1), respectively, must be defined consistently so that

and

For further information see Dzieciol et al. (1999), Thompson and Barnett (1986), and Humblet (1984).