Downsizing from the point of view of merging model (preliminary
  discussion)
  In four-particle scattering processes with transfer of mass, unlike mergers
in which mass can only increase, mass of the most massive galaxies may be
reduced. Elementary model describing such process is considered. In this way,
it is supposed to explain observed phenomenon of downsizing when increasing of
characteristic mass the heaviest galaxies over cosmological time replaces by
its reduction.
