Equation Icon  1 ⟨(ξ0i)k(η1)(ξ0i)− k(η2)⟩s = 2⟨{(ˆt0i)k(η1),(ˆt0i)−k(η2)}⟩φϕ (176 ) 1 = -kikiφ′(η1)φ′(η2)G (k1)(η1,η2), (177 ) 2