Though widely accepted, it is not proven that the supermassive central object (SMCO) of the Milky Way is a black hole. The SMCO could be a giant nontopological soliton, Q-ball, made of a scalar field. This fits perfectly all observational data. Similar but tiny Q-balls produced in the early Universe may constitute the dark matter. This may explain, why our SMCO has incredibly low accretion rate? Why the angular size of the corresponding radio source is smaller than the horizon size? How SMCOs were seeded in galaxies? etc.
