Equation Icon  1 δWk α α 1 δWk 1 δWk ¯fαβ = ⟨fαβ⟩ = √-¯g---αβ, σ = ⟨C ⟩ = √-¯g-δj--, ¯σα = ⟨C¯α⟩ = √-¯g-δjα-. (4.6 ) δJ∗ ∗,α ∗