AIC, BIC, Bayesian evidence against the interacting dark energy model

TL;DR

This paper evaluates the interacting dark energy model against the standard $\\Lambda$CDM model using current astronomical data and model selection criteria, finding strong evidence against the interaction model.

Contribution

It applies AIC, BIC, and Bayesian evidence to compare interacting and non-interacting dark energy models using recent observational data.

Findings

AIC favors the standard model over the interacting one.

BIC provides strong evidence against the interacting model.

Overall, the interacting dark energy model is rejected based on current data.

Abstract

Recent astronomical observations have indicated that the Universe is in the phase of accelerated expansion. While there are many cosmological models which try to explain this phenomenon, we focus on the interacting $\Lambda$CDM model where the interaction between the dark energy and dark matter sectors takes place. This model is compared to its simpler alternative---the $\Lambda$CDM model. To choose between these models the likelihood ratio test was applied as well as the model comparison methods (employing Occam's principle): the Akaike information criterion (AIC), the Bayesian information criterion (BIC) and the Bayesian evidence. Using the current astronomical data: SNIa (Union2.1), $h(z)$, BAO, Alcock--Paczynski test and CMB we evaluated both models. The analyses based on the AIC indicated that there is less support for the interacting $\Lambda$CDM model when compared to the $\Lambda$CDM model, while those based on the BIC indicated that there is the strong evidence against it in favor the $\Lambda$CDM model. Given the weak or almost none support for the interacting $\Lambda$CDM model and bearing in mind Occam's razor we are inclined to reject this model.