Probing Backreaction Effects with Supernova Data
  As the Einstein equations are non-linear, spatial averaging and temporal
evolution do not commute. Therefore, the evolution of the averaged universe is
affected by inhomogeneities. It is, however, highly controversial how large
these cosmological backreaction effects are. We use the supernova data of the
Constitution set up to a redshift of 0.1 in order to analyse to what extent the
measurement of the Hubble constant is affected. The size of the effect depends
on the size of the volume that is averaged over. The observational results are
then compared to the theory of the backreaction mechanism.
