Coincidence problem within dark energy as a coupled self-interacting
  Bose-Einstein gas
  A late accelerated expansion of the Universe is obtained from
non-relativistic particles with a short-range attractive interaction, and low
enough temperature to produce a Bose-Einstein condensate; by considering
coupled dark-energy particles, energy is interchanged with dark matter,
allowing it to describe recent acceleration by strengthening its effect. We
show that for a sizable range of parameters, dark energy and dark matter evolve
with similar energy densities, solving the coincidence problem, and in
agreement with the luminosity distance vs redshift, derived from supernova
data.
