Equation Icon  ∑ℓ (2ℓ − j)! uℓm↖ (t,r) = a†ℓa†ℓ−1...a†1Vℓm (r + t) = (− 1)j---------(2r)j−ℓVℓ(jm)(r + t), j=0 (ℓ − j)!j! ℓ † † † ∑ j-(2-ℓ −-j)! j−ℓ (j) uℓm↗ (t,r) = aℓaℓ−1...a1U ℓm (r − t) = (− 1) (ℓ − j)!j!(2r) U ℓm (r − t), (5.144 ) j=0