Vm. Eleonsky et Vg. Korolev, ON THE NONLINEAR GENERALIZATION OF THE FOCK METHOD, Journal of physics. A, mathematical and general, 28(17), 1995, pp. 4973-4985
The generalize Fock method is presented in the case of nonlinear depen
dence of the number-of-quanta operator on the Hamiltonian operator. Th
at generalization is used for an analysis of the inverse problem in th
e case of strictly discrete spectra in R(1). The relationship between
the quantum description on a basis of the Fock approach and the classi
cal limit of this description is analysed.