Ja. Neto et W. Oliveira, Does the Weyl ordering prescription lead to the correct energy levels for the quantum particle on the D-dimensional sphere?, INT J MOD P, 14(23), 1999, pp. 3699-3713
The energy eigenvalues of the quantum particle constrained in a surface of
the sphere of D dimensions embedded in a RD+1 space are obtained by using t
wo different procedures: in the first, we derive the Hamiltonian operator b
y squaring the expression of the momentum, written in Cartesian components,
which satisfies the Dirac brackets between the canonical operators of this
second-class system. We use the Weyl ordering prescription to construct th
e Hermitian operators. When D = 2 we verify that there is no constant param
eter in the expression of the eigenvalues energy, a result that is in agree
ment with the fact that an extra term would change the level spacings in th
e hydrogen atom; in the second procedure it is adopted the non-Abelian BFFT
formalism to convect the second-class constraints into first-class ones. T
he non-Abelian first-class Hamiltonian operator is symmetrized by also usin
g the Weyl ordering rule. We observe that their energy eigenvalues differ f
rom a constant parameter when we compare with the second-class system. Thus
, a conversion of the D-dimensional sphere second-class system for a first-
class one does not reproduce the same values.