Equation Icon  ∑ (1,−1) L ∑ (1,−1) L− 1 0 = − (ℓ + 1)(ℓ + 2 )B ˆL ˆωa − ℓ(ℓ − 1 )C ˆaL−1 ˆω ℓ≥0 ℓ≥1 ∑ ˆ(1,−1) L− 1 − ℓ(ℓ + 1)𝜖abcD cL−1 ˆωb , (22.23 ) ℓ≥1