  Astrophysical observations provide a picture of the universe as a 4-dim
homogeneous and isotropic flat space-time dominated by an unknown form of dark
energy. To achieve such a cosmology one has to consider in the early universe
an inflationary era able to overcome problems of standard cosmological models.
Here an inhomogeneous model is proposed which allows to obtain a
Friedmann-Robertson-Walker behaviour far away from the inhomogeneities and it
naturally describes structures formation. We also obtain that the cosmological
term does not prevent structure formation, avoiding a fine tuning problem in
initial conditions. The asymptotic exact solution have been calculated. A
simple test with universe age prediction has been performed. A relation between
the inhomogeneity, the breaking of time reversal, parity and the
matter-antimatter asymmetry is briefly discussed.
