Self-similar kinetics for gravitational Bose-Einstein condensation

We study an overpopulated gas of gravitationally interacting bosons surrounding a droplet of Bose-Einstein condensate---the Bose star. We argue that kinetic evolution of this gas approaches with time a self-similar attractor solution to the kinetic equation. If the scale symmetry of the equation is broken by external conditions, the attractor solution exists, remains approximately self-similar, but has a slowly drifting scaling dimension. The latter new regime of adiabatic self-similarity can determine growth of dark matter Bose stars in cosmological models.