Equation Icon  ∫ τ− ( ) ( ) htail = 4m ∇ λ G+ μνμ′ν′ − 1-gμνG ρ ′ ′ z(τ),z(τ′) uμ′uν′d τ′. (1.47 ) μνλ −∞ 2 + ρμ ν