Constraints on the interaction of quintessence dark energy with dark matter and the evolution of its equation of state parameter

The cosmological model with an interaction between dynamical quintessence dark energy and cold dark matter is considered. Evolution of a dark energy equation of state parameter is defined by a dark energy adiabatic sound speed and a dark sector interaction parameter, which must be more physically correct model then a previously used in which such evolution was given by some fixed dependence on scale factor. The constraints on interaction parameter and other parameters of the model was obtained using a cosmic microwave background, baryon acoustic oscillations and supernova SN Ia data.