Signature of the interaction between dark energy and dark matter in galaxy clusters

TL;DR

This paper explores how an interaction between dark energy and dark matter affects galaxy cluster dynamics, deriving a modified virial theorem and constraining the interaction strength using observational data.

Contribution

It introduces a generalized Layser-Irvine equation accounting for dark sector interactions and provides observational constraints on the coupling strength.

Findings

Coupling between dark energy and dark matter is small but positive.

Dark energy may decay into dark matter.

Modified virial theorem accounts for dark sector interaction.

Abstract

We investigate the influence of an interaction between dark energy and dark matter upon the dynamics of galaxy clusters. We obtain the general Layser-Irvine equation in the presence of interactions, and find how, in that case, the virial theorem stands corrected. Using optical, X-ray and weak lensing data from 33 relaxed galaxy clusters, we put constraints on the strength of the coupling in the dark sector. We find that this coupling is small but positive, indicating that dark energy can be decaying into dark matter.