Probing the sign-changeable interaction between dark energy and dark matter with DESI baryon acoustic oscillations and DES supernovae data

TL;DR

This study uses recent observational data, including DESI BAO and DES supernovae, to constrain models of dark energy and dark matter interaction that can change sign over cosmic time, revealing a preference for such models over standard cosmology.

Contribution

The paper introduces and constrains four general models of sign-changeable dark energy-dark matter interaction using latest observational data, highlighting the dynamic nature of the coupling.

Findings

The interaction coupling crosses zero during cosmic evolution in three models.

Energy transfer direction varies with cosmic dominance of dark energy or dark matter.

Some models are moderately favored over the standard ΛCDM model.

Abstract

There is a possibility of interaction between dark energy and dark matter, and this interaction may also undergo a sign change during the evolution of the universe. In this paper, we utilize the latest observational data to constrain models of a sign-changeable interaction. The data we employ, in addition to the cosmic microwave background data, also encompass the first-year baryon acoustic oscillation data from DESI and the type Ia supernova data of the full 5-year observation from DES. To achieve high generality, we investigate four interacting dark energy (IDE) models with different forms of the interaction term $Q$: (i) IDE1 with $Q = \beta(a)H\rho_{\rm de}$; (ii) IDE2 with $Q = \beta(a)H\rho_{\rm c}$; (iii) IDE3 with $Q = \beta(a)H_0\rho_{\rm de}$; (iv) IDE4 with $Q = \beta(a)H_0\rho_{\rm c}$. From the analysis, we observe that $\beta(z) > 0$ at early times and $\beta(z) < 0$ at late times, with the coupling $\beta(z)$ crossing the non-interacting line $\beta(z) = 0$ during cosmic evolution at the 2$\sigma$ confidence level for the IDE1, IDE3, and IDE4 models. However, for the IDE2 model, $\beta(z)$ remains consistently negative and does not cross $\beta(z) = 0$ at the 2$\sigma$ confidence level. Our findings indicate that the energy transfer is from dark matter to dark energy when dark matter dominates the universe, and from dark energy to dark matter when dark energy dominates, for the IDE1 and IDE3 models. Furthermore, Bayesian evidence suggests that the IDE1 and IDE3 models are moderately preferred over the $\Lambda$CDM model. The overall outcomes of this study clearly indicate that, based on current observational data, the sign-changeable IDE models are quite compelling and merit further attention.