Location: Cape Town Workshop: GR Effects in Cosmological Surveys
Traditionally structure formation in the Universe is dealt with Newtonian N-body simulations. Solving the mystery of Dark Energy is one of the fundamental questions of today’s physics, and “backreactionistas”have argued that the observed acceleration of the cosmic expansion maybe due to the nonlinear effect of structure formation when studied with Einstein Equations. This would be a non-perturbative effect that can only be fully investigated in numerical relativity. In addition, the high precision that will be reached by future galaxy surveys requires more precise theoretical predictions for structure formation. In this talk I will summarise results obtained with the first fully relativistic cosmological simulations, showing that – at least for the cases so far explored – back reaction is very small. However, at this stage we can’t exclude that its contribution to the overall expansion is entirely negligible. Finally, I will illustrate how fully relativistic simulations could be important in view of future high-precision galaxy surveys.