Joint analysis of EDGES $21$-cm line observations with standard candles and rulers in $\Lambda$CDM and non-adiabatic gCg models

Abstract

A decomposed generalised Chaplygin gas (gCg) with energy flux from dark energy to dark matter, represented by a negative value for the gas parameter $\alpha$, is shown to alleviate the tension between EDGES data and the cosmological standard model. Using EDGES data and employing a Bayesian statistical analysis, the agreement with the standard model is only marginal. However, if $\alpha$ is negative enough the gCg fits remarkably well the data, even in combination with SNe Ia datasets. On the other hand, when the CMB and BAO acoustic scales are included the preferred value for $\alpha$ is near zero, implying that a small deviation from $\Lambda$CDM is predicted.