  Clebsch-Gordan coefficients of SU(2) and SU(1,1) are defined as
eigenfunctions of a linear operator acting on the tensor product of the Hilbert
spaces for two irreps of these groups. The shifted harmonic approximation is
then used to solve these equations in asymptotic limits in which these
eigenfunctions approach harmonic oscillator wave functions and thereby derive
asymptotic expressions for these Clebsch--Gordan coefficients.
