How the geometric calculus resolves the ordering ambiguity of quantum theory in curved space

The long standing problem of the ordering ambiguity in the definition of the Hamilton operator for a point particle in curved space is naturally resolved by using the powerful geometric calculus based on Clifford algebra. The momentum operator is defined to be the vector derivative (the gradient) multiplied by -i; it can be expanded in terms of basis vectors (gamma)(mu) as p = i(gamma)(mu) (partial differential) (mu). The product of two such operators is unambiguous, and such is the Hamiltonian which is just the dʹAlembert operator in curved space; the curvature scalar term is not present in the Hamiltonian if we confine our consideration to scalar wavefunctions only. It is also shown that p is Hermitian and a self-adjoint operator: the presence of the basis vectors (gamma)(mu) compensates the presence of (radical sign)|g| in the matrix elements and in the scalar product. The expectation value of such an operator follows the classical geodetic line.