How large is the contribution of cosmic web to $\Omega_\Lambda$ ? A
  preliminary study on a novel inhomogenous 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
($\Lambda$FB model) of the Fractal Bubble model, proposed by Wiltshire, which
accounts for such large scale structure. The $\Lambda$FB model is an evolution
of FB model and includes in a consistent way a description of inhomogeneous
matter distribution and a $\Lambda$ term. Here we analyze the $\Lambda$FB model
focusing on the relation between cosmological parameters. The main result is
the consistency of $\Lambda$CDM model values for $\Omega_{\Lambda0}$ ($\approx
0.7$) and $\Omega_{k0}$ ($|\Omega_{k0}|<\approx 0.01$) with a large fraction of
voids. This allows to quantify to which extent the inhomogeneous structure
could account for $\Lambda$ constant consistently with standard values of the
other cosmological parameters.
