Szekeres models the Zeldovich approximation and multi structure collapse

We examine the evolution and collapse of multiple 30 100 Mpc sized pancake and filament shaped CDM structures constructed by means of the Szekeres dust models The dynamics of these structures is equivalent to a fully relativistic generalization of the Zeldovich approximation thus allowing for a fully relativistic generalization of the Newtonian spherical and elliptic collapse models used in numerical simulations The Szekeres multi structure models are potentially useful in fitting observations whenever a non perturbative and fully relativistic approach is needed