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

Understand

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 $Q = \beta(a)H_0\rho_{\rm c}$.