Reconstructing the statefinder hierarchy for an interacting cosmology

This paper studies an interacting cosmology in a spatially flat universe. Here, we have reconstructed the interaction term, Q, between a cold dark matter (DM) fluid and a dark energy (ω_DE) fluid, as well as a time-varying equation of state (EoS) parameter DE, and have explored its evolutionary trajectories in the second members of the statefinder hierarchy, allowing us to establish differences when they are compared with those obtained in other non-interacting models. Likewise, both Q and ω_DE have been modeled in terms of the Chebyshev polynomials. Then, via a Markov chain Monte Carlo (MCMC) method, we have constrained the model parameter space by using a combined analysis of geometric data. Our results show that an interacting model can be distinguished well from the standard concordance model at the present time by using any combination of the second members of the statefinder hierarchy. In this way, different DE scenarios could be compared and distinguished between them. (author)