Towards statistically homogeneous and isotropic perfect fluid universes with cosmic backreaction

Understand

A method for constructing statistically homogeneous and isotropic perfect fluid universe models with significant cosmic backreaction is proposed.

• The method is illustrated using a simplified model constructed as a Swiss-cheese model with Lemaitre-Tolman-Bondi structures.
• The model exhibits significant cosmic backreaction and is used to study methods proposed in the literature for relating volume averaged quantities with observations.
• The comparison shows a poor agreement between exact redshift-distance relations and the relations predicted by schemes based on volume averages.