1/N-EXPANSION FOR THE KLEIN-GORDON EQUATION

An effective method for calculating the 1/N-expansion coefficients for the discrete spectrum of the Klein - Gordon equation is developed. Based on the use of the h-expansion and quantization conditions, the method leads to the simple recurrence formulae which allow to derive the coefficients of arbitrary high orders both for the ground and radially excited states. As an example, the calculations of the energy eigenvalues for the Coulomb interaction and the funnel-shaped potential are considered within the 1/n-expansion scheme.