Constraining the dark matter-vacuum energy interaction using the EDGES 21-cm absorption signal

TL;DR

This study explores how an interaction between dark matter and vacuum energy can reconcile the EDGES 21-cm absorption signal with standard cosmological models, highlighting the potential of future 21-cm observations.

Contribution

It introduces a model where dark matter interacts with vacuum energy to explain the EDGES signal and assesses its constraints using combined cosmological data.

Findings

Interaction model can alleviate tension with EDGES data

Combined data slightly favors standard $\\Lambda$CDM model

Future 21-cm experiments could better constrain dark energy interactions

Abstract

The recent measurement of the global 21-cm absorption signal reported by the Experiment to Detect the Global Epoch of Reionization Signature (EDGES) Collaboration is in tension with the prediction of the $\Lambda$CDM model at a $3.8\,\sigma$ significance level. In this work, we report that this tension can be released by introducing an interaction between dark matter and vacuum energy. We perform a model parameter estimation using a combined dataset including EDGES and other recent cosmological observations, and find that the EDGES measurement can marginally improve the constraint on parameters that quantify the interacting vacuum, and that the combined dataset favours the $\Lambda$CDM at 68\% CL. This proof-of-the-concept study demonstrates the potential power of future 21-cm experiments to constrain the interacting dark energy models.