Substituting this density and charge current into the wave equation, we can solve for the Fourier-form potentials: Φ Φ ( k → → , ω ω ) = 2 q ε ε ( ω ω ) δ δ ( ω ω − − k → → ⋅ ⋅ v → → ) k 2 − − ω ω 2 c 2 ε ε ( ω ω ) and A → → ( k → → , ω ω ) = ε ε ( ω ω ) v → → c Φ Φ ( k → → , ω ω )