Published online by Cambridge University Press: 14 August 2015
Evolutionary changes of masses and periods under the influence of gravitational radiation (GR) are computed for binaries with main-sequence or degenerate hydrogen-helium (H), helium (He) and carbon (C) secondaries. Tracks in the P-M2 and P-M2 planes are determined. The orbital period of systems P with a non-degenerate dwarf filling its Roche lobe decreases until the time-scale of GR (~ 109−1010yrs) becomes shorter than the thermal time-scale τKH of the mass losing component M2. When M2 becomes ~ 0.1 M⊙, P begins to increase. This could account for the existence of the minimal P ≈ 1.3h and for the accumulation of observed cataclysmic binaries (CB) below P ≤ 2h. The GR can be the driving force for evolution of cataclysmic binaries: TT Ari, OY Car, Z Cha, and WZ Sge as their P, M2 and indicate. The rate of mass exchange driven by GR is ~ 10−9−10−10 M⊙/yrs. It is enough to feed the X-ray bursters and related objects.