Abstract:
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
Λ
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
Λ
CDM
cosmology while one of them has no fine-tuning problem. We also show that our model satisfies the observational local constraints on
˙
G
/
G
.