equation icon  integral ( ) Dab =_ V~ -1--d-- dnx V~ --g RcdefRcdef - RcdRcd - gdgab gab( ) = --- RcdefRcdef- RcdRcd + []R - 2RacdeRbcde- 2RacbdRcd + 4RacRcb - 3[]Rab + \~/ a\ ~/ bR. 2 (30)