Eigenvalue, Quantum Physics.
Consider the angular wavefunction ψ(θ, φ) = L+ Yl,m(θ, φ). We know that since ψ∗ ψ ≡ |ψ|2 is a positive-definite real quantity. Hence, we find that We, thus, obtain the constraint Likewise, the inequality leads to a second constraint Without loss of generality, we can assume that l ≥ 0. This is