Abstract:
The dominance of dark energy in the universe has
necessitated the introduction of a repulsive gravity source to
make q0 negative. The models for dark energy range from a
simple term to quintessence, Chaplygin gas, etc. We look
at the possibility of how change of behaviour of missing energy
density, from DM to DE, may be determined by the
change in the equation of state of a background fluid instead
of a form of potential. The question of cosmic acceleration
can be discussed within the framework of theories which do
not necessarily include scalar fields.
