Speaker: Cornelius Rampf

The first part of the talk is devoted to current developments to the cosmological structure formation within the Newtonian picture. In particular, I show how to obtain exact (i.e., to arbitrary high accuracy) perturbative solutions for the fully non-linear fluid equations in Lambda CDM. These findings could assist to close significantly the gap between analytical and numerical tools. Applications to these findings are for example the study of shell-crossing (blowup) or the cosmological reconstruction problem, or any other phenomenon where high spatial resolution is required. In the second part of the talk I show how general relativistic effects can be effectively described in Newtonian N-body simulations. I define a new gauge, the N-body gauge, and show that a conventional Newtonian simulation includes all first-order relativistic corrections if the coordinates in the Newtonian simulation are identified with those in the N-body gauge.