Equation Icon  2 R μν(g) − 1gμνR (g) = κ-Tμν-− FR-(T-) −-f-gμν + 1-(∇ μ∇ νF − gμν□F ) 2 F [ 2F F ] -3-- 1- 2 − 2F 2 ∂μF ∂νF − 2 gμν(∇F ) . (9.4 )