HOW LARGE IS THE CONTRIBUTION OF COSMIC WEB TO ΩΛ? A PRELIMINARY STUDY ON A NOVEL INHOMOGENEOUS MODEL

The distribution of matter in the universe shows a complex pattern, formed by cluster of galaxies, voids and filaments denoted as cosmic web. Different approaches have been proposed to model such structure in the framework of the general relativity. Recently, one of us has proposed a generalization (ΛFB model) of the Fractal Bubble model, proposed by Wiltshire, which accounts for such large scale structure. The ΛFB model is an evolution of FB model and includes in a consistent way a description of inhomogeneous matter distribution and a Λ term. Here, we analyze the ΛFB model focusing on the relation between cosmological parameters. The main result is the consistency of ΛCDM model values for ΩΛ0 (≈ 0.7) and Ωk0 (|Ωk0| <≈ 0.01) with a large fraction of voids. This allows to quantify to which extent the inhomogeneous structure could account for Λ constant consistently with standard values of the other cosmological parameters.