Relieving the H 0 tension with a new interacting dark energy model

Abstract

We investigate an extended cosmological model motivated by the asymptotic safety of gravitational field theory, in which the matter and radiation densities and the cosmological constant receive a correction parametrized by the parameters δ G and δ Λ , leading to that both the evolutions of the matter and radiation densities and the cosmological constant slightly deviate from the standard forms. Here we explain this model as a scenario of vacuum energy interacting with matter and radiation. We consider two cases of the model: (i) Λ̃CDM with one additional free parameter δ G , with δ G and δ Λ related by a low-redshift limit relation and (ii) eΛ̃CDM with two additional free parameters δ G and δ Λ that are independent of each other. We use two data combinations, CMB+BAO+SN (CBS) and CMB+BAO+SN+H 0 (CBSH), to constrain the models. We find that, in the case of using the CBS data, neither Λ̃CDM nor eΛ̃CDM can effectively alleviate the H 0 tension. However, it is found that using the CBSH data the H 0 tension can be greatly relieved by themodels. In particular, in the case of eΛ̃CDM, the H 0 tension can be resolved to 0.71σ. We conclude that as an interacting dark energy model, Λ̃CDM is much better than Λ(t)CDM in the sense of both relieving the H 0 tension and fitting to the current observational data.