Spinning, Precessing, Black Hole Binary Spacetime via Asymptotic
  Matching
  We briefly discuss a method to construct a global, analytic, approximate
spacetime for precessing, spinning binary black holes. The spacetime
construction is broken into three parts: the inner zones are the spacetimes
close to each black hole, and are approximated by perturbed Kerr solutions; the
near zone is far from the two black holes, and described by the post-Newtonian
metric; and finally the wave (far) zone, where retardation effects need to be
taken into account, is well modeled by the post-Minkowskian metric. These
individual spacetimes are then stitched together using asymptotic matching
techniques to obtain a global solution that approximately satisfies the
Einstein field equations. Precession effects are introduced by rotating the
black hole spin direction according to the precessing equations of motion, in a
way that is consistent with the global spacetime construction.
