A convincing explanation for the nature of the dark energy and dark matter is still missing. In recent works a RG-improved swiss-cheese cosmology with an evolving cosmological constant dependent on the Schücking radius has been proven to be a promising model to explain the observed cosmic acceleration. In this work we extend this model to consider the combined scaling of the Newton constant $G$ and the cosmological constant $\mathrm{\Lambda }$ according to the IR-fixed point hypothesis. We shall show that our model easily generates the observed recent passage from deceleration to acceleration without need of extra energy scales, exotic fields or fine-tuning. In order to check the generality of the concept, two different scaling relations have been analyzed and we proved that both are in very good agreement with $\mathrm{\Lambda }\mathrm{CDM}$ cosmology while one of them has no fine-tuning problem. We also show that our model satisfies the observational local constraints on $\dot{G}/G$.

• Received 10 January 2022
• Accepted 1 April 2022

DOI:https://doi.org/10.1103/PhysRevD.105.083532