Equation Icon  ∑∞ E (t) ≃ ℰ cosω t − δm-ℰ0 Φ {sin[(ω − kΩ )t − ϕ ] + sin [(ω + k Ω)t + ϕ ]} PM 0 0 2 k 0 k 0 k [ k=1 ] −iω0t iδmℰ0-∑∞ { −i[(ω0−kΩ)t−ϕk] − i[(ω0+kΩ)t+ϕk]} = Re ℰ0e + 2 Φk e + e , (23 ) k=1