Evolution of Close Binaries: Formation and Merger of Neutron Star   Binaries
  We discuss the formation and evolution of binaries which contain neutron stars or black holes. It is shown that in a stellar system which for $10^{10}$ yr had star formation rate similar to the current one in the Galactic disc, the rate of neutron star mergers is $\sim 2 \times 10^{-5} yr{-1}$, consistent with the observational estimates. The rate of black hole and neutron star mergers is by an order of magnitude lower. The pairs of black holes form but do not merge because heavy mass loss by their progenitors efficiently moves the binary components apart. 
Lev Yungelson (INASAN, Moscow, Russia), Simon F. Portegies Zwart   (Astronomical Institute ``Anton Pannekoek'', Amsterdam, T...