Self-similar kinetics for gravitational Bose-Einstein condensation

We study an overpopulated gas of gravitationally interacting bosons surrounding a droplet of Bose-Einstein condensate - 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 slowly drifting scaling dimension. The latter new regime of adiabatic self-similarity can determine growth of dark matter Bose stars in cosmological models.

A.S. Dmitriev, D.G. Levkov, A.G. Panin, I.I. Tkachev · 2025