  The main goal of this paper is deriving Density of states $g(\epsilon)$
(degeneracy function) per volume for an equation of state (EOS) $p=-\rho$ (we
called it dark energy(DE)).We have concluded that thermodynamic quantities such
as pressure and energy density are simple functions of temperature, fugacity,
curvature and mass of Bosons. Our work has been expressed the origin of some
claims about the negativity of the entropy for the scalar fields models of DE.
