Equation Icon  − ℓ2Gˆμν = 2ℓ(ˆ∇ μˆ∇ νℓ − ˆgμν∇ˆα∇ˆα ℓ) + 3ˆgμν(ˆ∇ αℓ)ˆ∇ αℓ. (70 )