  The numerical relativity session at GR18 was dominated by physics results on
binary black hole mergers. Several groups can now simulate these from a time
when the post-Newtonian equations of motion are still applicable, through
several orbits and the merger to the ringdown phase, obtaining plausible
gravitational waves at infinity, and showing some evidence of convergence with
resolution. The results of different groups roughly agree. This new-won
confidence has been used by these groups to begin mapping out the
(finite-dimensional) initial data space of the problem, with a particular focus
on the effect of black hole spins, and the acceleration by gravitational wave
recoil to hundreds of km/s of the final merged black hole. Other work was
presented on a variety of topics, such as evolutions with matter, extreme mass
ratio inspirals, and technical issues such as gauge choices.
