Testing the interaction between dark energy and dark matter via latest observations

TL;DR

This paper investigates the potential interaction between dark energy and dark matter using recent observational data, aiming to identify signatures and constraints that could clarify their coupling and address the coincidence problem.

Contribution

It provides a comprehensive analysis of dark sector coupling, employing perturbation formalism and global fitting to constrain interaction parameters with latest data.

Findings

Tight constraints on dark sector interaction parameters.

Interaction can help alleviate the coincidence problem.

Degeneracy with other cosmological parameters is a key challenge.

Abstract

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.