Alexander Wiegand (Universitaet Bielefeld)
Zel’dovich’s approximation is in Newtownian cosmology a practical tool to investigate the evolution of mildly nonlinear regions of the Universe. Its extension to the relativistic case is important for the investigation of the backreaction of inhomogeneities on the evolution history of spatial domains of the Universe. This talk presents a Lagrangian framework that allows for a one to one correspondence of Newtownian and general relativistic quantities and provides a non-perturbative backreaction model, together with domain-dependent quantitiative estimates of the backreaction effect.
Alexander Wiegand (Universitaet Bielefeld) Charly Nayet (ENS Lyon) Thomas Buchert (Université Lyon 1)