Equation Icon  ∫ ∘ ------2- ρ (x ) = 3 1 + |v| f(x,v)dv, (58 ) ∫ℝ ( )2 p (x ) = x-⋅ v f(x,v) ∘--dv----. (59 ) ℝ3 r 1 + |v|2