Observations in statistically homogeneous, locally inhomogeneous cosmological toy-models without FLRW backgrounds. (arXiv:2008.07108v3 [astro-ph.CO] UPDATED)

Observations in statistically homogeneous, locally inhomogeneous cosmological toy-models without FLRW backgrounds. (arXiv:2008.07108v3 [astro-ph.CO] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Koksbang_S/0/1/0/all/0/1">S. M. Koksbang</a>

Observations are studied in toy-models constituting exact cosmological
solutions to the Einstein equation which are statistically homogeneous but
locally inhomogeneous, without an a priori introduced FLRW background and with
“structures” evolving fairly slowly. The mean redshift-distance relation and
redshift drift along 500 light rays in each of two models are compared to
relations based on spatial averages. The relations based on spatial averages
give a good reproduction of the mean redshift-distance relation, although most
convincingly in the model where the kinematical backreaction is subpercent. In
both models, the mean redshift drift clearly differs from the drift of the mean
redshift. This indicates that redshift drift could be an important tool for
testing the backreaction conjecture as redshift drift appears to distinguish
between local and global effects. The method presented for computing the
redshift drift is straightforward to generalize and can thus be utilized to
fairly easily compute this quantity in a general spacetime.

Observations are studied in toy-models constituting exact cosmological
solutions to the Einstein equation which are statistically homogeneous but
locally inhomogeneous, without an a priori introduced FLRW background and with
“structures” evolving fairly slowly. The mean redshift-distance relation and
redshift drift along 500 light rays in each of two models are compared to
relations based on spatial averages. The relations based on spatial averages
give a good reproduction of the mean redshift-distance relation, although most
convincingly in the model where the kinematical backreaction is subpercent. In
both models, the mean redshift drift clearly differs from the drift of the mean
redshift. This indicates that redshift drift could be an important tool for
testing the backreaction conjecture as redshift drift appears to distinguish
between local and global effects. The method presented for computing the
redshift drift is straightforward to generalize and can thus be utilized to
fairly easily compute this quantity in a general spacetime.

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