  The evolution of cosmological large-scale perturbations is described in terms
of the concordant model based on the recent discovery of cosmic vacuum. It is
demonstrated that the process is robustly controlled by a few epoch-independent
physical parameters. The parameters guarantee that the initially weak
perturbations become nonlinear before (but near) the termination of
gravitational instability by cosmic vacuum. No fine tuning for the perturbation
amplitude is needed.
