Equation Icon  ( ) U αβ′ ′ = 1-g(α′gβ)′gšœ–′šœ– Rα′γ′šœ–′ι′δβ′′ + Rαδ′′šœ–′ι′δβ′′ σ ι′ + O (λ2 ), (16.14 ) γ δ;šœ– 2 α β ( δ )γ αβ 1- (α β) α′ β′ α′ β′ ι′ 2 U γ′δ′;šœ–′ = 2 g α′g β′ R γ′šœ–′ι′δ δ′ + R δ′šœ–′ι′δ γ′ σ + O (λ ), (16.15 )