A two- or three-dimensional quantal isotropic anharmonic oscillator is treated by means of the phase-integral method of Fröman and Fröman. The generalized Bohr-Sommerfeld quantization condition for the radial wave function is expressed in terms of complete elliptic integrals up to the fifth order of the phase-integral approximation. The quantization condition is solved numerically, and energy levels are obtained for various quantum numbers. Comprison with numerically exact results is also made.

• Received 14 December 1993

DOI:https://doi.org/10.1103/PhysRevA.49.3296