Reviving a small simulation (2D in Julia) to show how the onset of cosmic structure formation can essentially be captured by the Zeldovich approximation - meaning you just keep displacing the initial distribution of particles following the path traced by the initial tiny gravitational perturbations, which are imprinted in the initial conditions.
Actual N-body dynamics will take place only at the first crossing of streams of particles (in filaments, halos..)
#simulatedUniverses #astrophysics