Breaking parameter degeneracy in interacting dark energy models from   observations
  We study the interacting dark energy model with time varying dark energy equation of state. We examine the stability in the perturbation formalism and the degeneracy among the coupling between dark sectors, the time-dependent dark energy equation of state and dark matter abundance in the cosmic microwave background radiation. Further we discuss the possible ways to break such degeneracy by doing global fitting using the latest observational data and we get a tight constraint on the interaction between dark sectors. 
Xiao-Dong Xu, Jian-Hua He, Bin Wang
astro-ph.CO gr-qc hep-ph hep-th