MOCCA-SURVEY Database I: Eccentric Black Hole Mergers During
  Binary-Single Interactions In Globular Clusters
  We estimate the population of eccentric gravitational wave (GW) binary black
hole (BBH) mergers forming during binary-single interactions in globular
clusters (GCs), using ~ 800 GC models that were evolved using the MOCCA code
for star cluster simulations as part of the MOCCA-Survey Database I project. By
re-simulating binary-single interactions (only involving 3 BHs) extracted from
this set of GC models using an N-body code that includes GW emission at the 2.5
post-Newtonian level, we find that ~ 10% of all the BBHs assembled in our GC
models that merge at present time form during chaotic binary-single
interactions, and that about half of this sample have an eccentricity > 0.1 at
10 Hz. We explicitly show that this derived rate of eccentric mergers is ~ 100
times higher than one would find with a purely Newtonian N-body code.
Furthermore, we demonstrate that the eccentric fraction can be accurately
estimated using a simple analytical formalism when the interacting BHs are of
similar mass; a result that serves as the first successful analytical
description of eccentric GW mergers forming during three-body interactions in
realistic GCs.
