Constraints on interacting dark energy models from Planck 2015 and
  redshift-space distortion data
  We investigate phenomenological interactions between dark matter and dark
energy and constrain these models by employing the most recent cosmological
data including the cosmic microwave background radiation anisotropies from
Planck 2015, Type Ia supernovae, baryon acoustic oscillations, the Hubble
constant and redshift-space distortions. We find that the interaction in the
dark sector parameterized as an energy transfer from dark matter to dark energy
is strongly suppressed by the whole updated cosmological data. On the other
hand, an interaction between dark sectors with the energy flow from dark energy
to dark matter is proved in better agreement with the available cosmological
observations. This coupling between dark sectors is needed to alleviate the
coincidence problem.
