Constraining interacting dark energy with CMB and BAO future surveys
  In this paper, we perform a forecast analysis to test the capacity of future
baryon acoustic oscillation (BAO) and cosmic microwave background (CMB)
experiments to constrain phenomenological interacting dark energy models using
the Fisher matrix formalism. We consider a Euclid-like experiment, in which BAO
measurements is one of the main goals, to constrain the cosmological parameters
of alternative cosmological models. Moreover, additional experimental probes
can more efficiently provide information on the parameters forecast, justifying
also the inclusion in the analysis of a future ground-based CMB experiment
mainly designed to measure the polarization signal with high precision. In the
interacting dark energy scenario, a coupling between dark matter and dark
energy modifies the conservation equations such that the fluid equations for
both constituents are conserved as the total energy density of the dark sector.
In this context, we consider three phenomenological models which have been
deeply investigated in literature over the past years. We find that the
combination of both CMB and BAO information can break degeneracies among the
dark sector parameters for all three models, although to different extents. We
found powerful constraints on, for example, the coupling constant when
comparing it with present limits for two of the models, and their future
statistical 3-$\sigma$ bounds could potentially exclude the null interaction
for the combination of probes that is considered. However, for one of the
models, the constraint on the coupling parameter does not improve the present
result (achieved using a large combination of surveys), and a larger
combination of probes appears to be necessary to eventually claim whether or
not interaction is favored in that context.
