Perturbation Growth in Anisotropic Cosmologies
  We study the growth of perturbations in an expanding Bianchi type-I metric that evolves according to an energy density that includes dust and a cosmological constant. Assuming an epoch where the cosmological constant is subdominant, we find that, for a reasonably large set of initial conditions, the metric fluctuations grow fast enough to make the metric inhomogeneous before the cosmological constant becomes the dominant form of energy. We have examined values for the cosmological constant that are in the interval $10^{10} {GeV}$ to $10^{16} {GeV}$. 
E. Dimastrogiovanni, W. Fischler and S.Paban