Equation Icon  [ ] [ ] ¯eα= 1 − 1r2a˙(u ) + O (r3) eα+ r(1 − a Ωb)aa(u) + 1-r2˙aa(u) + 1r2Ra (u)Ωb + O (r3) eα(.11.7 ) 0 2 0 0 b 2 2 0b0 a