Population Synthesis for Progenitors of Type Ia Supernovae
  We discuss application of population synthesis for binary stars to progenitors of SN Ia. We show that the only candidate systems able to support the rate of SNe Ia $\sim 10^{-3} yr^{-1}$ both in old and young populations are merging white dwarfs. In young populations ($\sim 1$ Gyr) edge-lit detonations in semidetached systems with nondegenerate helium star donors are also able to support a similar rate. The estimated current Galactic rate of SN Ia with single-degenerate progenitors is $\sim 10^{-4} yr^{-1}$. 
Lev R. Yungelson