31 Heun Functions31.2 Differential Equations

§31.1 Special Notation

(For other notation see Notation for the Special Functions.)

x, y real variables.
z, \zeta, w, W complex variables.
j, k, \ell, m, n nonnegative integers.
a complex parameter, |a|\geq 1,a\neq 1.
q,\alpha,\beta,\gamma,\delta,\epsilon,\nu complex parameters.

The main functions treated in this chapter are \mathop{\mathit{H\!\ell}\/}\nolimits\!\left(a,q;\alpha,\beta,\gamma,\delta;z\right), \mathop{(s_{1},s_{2})\mathit{Hf}_{{m}}\/}\nolimits\!\left(a,q_{m};\alpha,\beta,\gamma,\delta;z\right), \mathop{(s_{1},s_{2})\mathit{Hf}_{{m}}^{{\nu}}\/}\nolimits\!\left(a,q_{m};\alpha,\beta,\gamma,\delta;z\right), and the polynomial \mathop{\mathit{Hp}_{{n,m}}\/}\nolimits\!\left(a,q_{{n,m}};-n,\beta,\gamma,\delta;z\right). These notations were introduced by Arscott in Ronveaux (1995, pp. 34–44). Sometimes the parameters are suppressed.