Equation Icon  2 K 8πG H + -2-= -----(ρd + ρM ), (13.17 ) a 3F H˙ − K--= − 4πG--(ρd + Pd + ρM + PM ), (13.18 ) a2 F ρ˙M + 3H (ρM + PM ) = 0, (13.19 )