Nonlinear gravitational growth inside and outside the standard cosmology

We reconsider the problem of nonlinear structure formation inside and outside General Relativity (GR), both in the weakly and strongly nonlinear regime. We show how these regimes can be explored observationally through clustering of high-order cumulants and through the epoch of formation, abundance and clustering of collapse structures, using Press and Schechter (1974, Astrophys. J. 187: 425-438) formalism and its extensions.