Testing the interaction between dark energy and dark matter via latest
  observations
  Cosmological analysis based on currently available observations are unable to
rule out a sizeable coupling between dark energy and dark matter. However, the
signature of the coupling is not easy to grasp, since the coupling is
degenerate with other cosmological parameters, such as the dark energy equation
of state and the dark matter abundance. We discuss the possible ways to break
such degeneracy. Based on the perturbation formalism, we carry out the global
fitting by using latest observational data and get a tight constraint on the
interaction between dark sectors. We find that the appropriate interaction can
alleviate the coincidence problem.
