Equation Icon  ℛ Λ,k(p,q ) = ℛk (p2)δΛ(p + q), lim δΛ(p) = δ(p), (C.3 ) Λ→∞ { k2 for p2 ≪ k2, ℛk (p2) ≈ 2 2 (C.4 ) 0 for k ≪ p .