Constraints on interacting dark energy models from Planck 2015 and redshift-space distortion data

TL;DR

This paper constrains models of dark matter and dark energy interaction using recent cosmological data, finding that energy transfer from dark energy to dark matter aligns better with observations and helps address the coincidence problem.

Contribution

It provides updated constraints on interacting dark energy models using Planck 2015 and other cosmological data, highlighting the preferred direction of energy transfer.

Findings

Interaction from dark matter to dark energy is suppressed by data.

Interaction from dark energy to dark matter is favored by observations.

Dark sector coupling can alleviate the coincidence problem.

Abstract

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.