𝒞 ν ( u ± v ) = ∑ k = − ∞ ∞ 𝒞 ν ∓ k ( u ) J k ( v ) \mathcal{C}_{\nu}\left(u\pm v\right)=\sum_{k=-\infty}^{\infty}\mathcal{C}_{\nu\mp k}\left(u\right)J_{k}\left(v\right)