Highly Influential

Asymptotic expansion of the second-order linear ordinary differential equation Ψ+kf(z)Ψ= 0, in which the real constant k is large and f =O(1), can be carried out in the manner of Liouville and Green provided f does not vanish. If f does vanish, however, at z0 say, then Liouville-Green expansions can be carried out either side of the turning point z = z0… (More)