Evolution of cosmological perturbations in Bose-Einstein condensate dark
  matter
  We consider the global cosmological evolution and the evolution of the
density contrast in the Bose-Einstein condensate dark matter model, in the
framework of a Post-Newtonian cosmological approach. In the Bose-Einstein
model, dark matter can be described as a non-relativistic, Newtonian
gravitational condensate, whose density and pressure are related by a
barotropic equation of state. For a condensate with quartic non-linearity, the
equation of state is polytropic with index $n=1$. The basic equation describing
the evolution of the perturbations of the Bose-Einstein condensate is obtained,
and its solution is studied by using both analytical and numerical methods. The
global cosmological evolution as well as the evolution of the perturbations of
the condensate dark matter shows significant differences with respect to the
pressureless dark matter model, considered in the framework of standard
cosmology. Therefore the presence of condensate dark matter could have modified
drastically the cosmological evolution of the early universe, as well as the
large scale structure formation process.
