# Generalized models of unification of dark matter and dark energy

(see N. Caplar, H. Stefancic, Generalized models of unification of dark matter and dark energy (arXiv: 1208.0449))

Problem 1

problem id: gmudedm_1

The equation of state of a barotropic cosmic fluid can in general be written as an implicitly defined relation between the fluid pressure $p$ and its energy density $\rho$, $F(\rho,p)=0.$ Find the speed of sound in such fluid.

Problem 2

problem id: gmudedm_2

For the barotropic fluid with a constant speed of sound $c_s^2=const$ find evolution of the parameter of EOS, density and pressure with the redshift.