Cosmic Large-Scale Structure Formation from Newtonian Particle Dynamics

We present results for the cosmic non-linear density-fluctuation power spectrum based on the analytical formalism developed in [1] which allows us to study cosmic structure formation based on Newtonian particle dynamics in phase-space. This framework provides a field-theory approach to a perturbative solution of the BBGKY-hierarchy where the resulting loop-expansion of the theory introduces a natural truncation criterion. We show that we are able to reproduce structure growth on large scales $k \leq 0.2 \mathrm{h}\,\mathrm{Mpc}^{-1}$ to very high precision while on small and intermediate scales we find deviations of the order of $10\%$ from current numerical simulations. The results strongly suggest that a significant improvement may be achieved by restructuring the perturbation theory.