  The inspiral merger time for two black holes captured into a nonrelativistic
bound orbit by gravitational radiation emission has been often calculated by a
formula of Peters that assumes the adiabatic approximation that the changes per
orbit are small. However, initially this is not true for the semimajor axis and
period of most of the initially highly eccentric orbits, which change
significantly during closest approach and much less elsewhere along the orbit.
This effect can make the merger time much longer (using other formulas from
Peters that do not assume the adiabatic approximation) than that calculated by
the adiabatic formula of Peters.
