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

There is a possibility of interaction between dark energy and dark matter, and it may undergo a sign change during the evolution of the universe. In this paper, we utilize the latest DESI baryon acoustic oscillation data, along with type Ia supernova data from DES and cosmic microwave background data from Planck and ACT, to constrain models of sign-changeable interaction. From our analysis, we observe that the coupling β(z) crosses the non-interacting line β(z) = 0 and changes sign from positive to negative during cosmic evolution. Specifically, we find that the existence of sign-changeable interaction in the model with Q = β(a)H₀ρ_de is supported by the current data at the 4.1σ 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 models with Q ∝ ρ_de. Furthermore, Bayesian evidence suggests that the Q ∝ ρ_de models are moderately preferred over the ACDM model. The overall outcomes of this study clearly indicate that, based on current observational data, the sign-changeable interacting dark energy models are quite compelling and merit further attention.