Density contrast indicators in cosmological dust models

We discuss ways of quantifying structuration in relativistic cosmological s ettings, by employing a family of covariant density constrast indicators. W e study the evolution of these indicators with time in the context of inhom ogeneous Szekeres models. We find that different observers (having either d ifferent spatial locations or different indicators) see different evolution s for the density contrast, which may or may not be monotonically increasin g with time. We also find that monotonicity seems to be related to the init ial conditions of the model, which may be of potential interest in connecti on with debates regarding gravitational entropy and the arrow of time.