Dynamical spatial curvature as a fit to type Ia supernovae. (arXiv:1902.07915v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Desgrange_C/0/1/0/all/0/1">Célia Desgrange</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Heinesen_A/0/1/0/all/0/1">Asta Heinesen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Buchert_T/0/1/0/all/0/1">Thomas Buchert</a>
Few statements in cosmology can be made without assuming a cosmological model Few statements in cosmology can be made without assuming a cosmological model http://arxiv.org/icons/sfx.gif
within which to interpret data. Statements about cosmic acceleration is no
exception to this rule, and the inferred positive volume acceleration of our
Universe often quoted in the literature is valid in the context of the standard
Friedmann-Lema^{i}tre-Robertson-Walker (FLRW) class of space-times. Using the
Joint Light-curve Analysis (JLA) catalogue of type Ia supernovae (SNIa), we
examine the fit of a class of exact scaling solutions with dynamical spatial
curvature formulated in the framework of a scalar averaging scheme for
relativistic inhomogeneous space-times. In these models, global volume
acceleration may emerge as a result of the non-local variance between expansion
rates of clusters and voids, the latter gaining volume dominance in the
late-epoch Universe. We find best-fit parameters for a scaling model of
backreaction that are reasonably consistent with previously found constraints
from SNIa, CMB, and baryon acoustic oscillations data. The quality of fit of
the scaling solutions is indistinguishable from that of the $Lambda$CDM model
and the timescape cosmology from an Akaike Information Criterion (AIC)
perspective. This indicates that a broad class of models can account for the
$z
within which to interpret data. Statements about cosmic acceleration is no
exception to this rule, and the inferred positive volume acceleration of our
Universe often quoted in the literature is valid in the context of the standard
Friedmann-Lema^{i}tre-Robertson-Walker (FLRW) class of space-times. Using the
Joint Light-curve Analysis (JLA) catalogue of type Ia supernovae (SNIa), we
examine the fit of a class of exact scaling solutions with dynamical spatial
curvature formulated in the framework of a scalar averaging scheme for
relativistic inhomogeneous space-times. In these models, global volume
acceleration may emerge as a result of the non-local variance between expansion
rates of clusters and voids, the latter gaining volume dominance in the
late-epoch Universe. We find best-fit parameters for a scaling model of
backreaction that are reasonably consistent with previously found constraints
from SNIa, CMB, and baryon acoustic oscillations data. The quality of fit of
the scaling solutions is indistinguishable from that of the $Lambda$CDM model
and the timescape cosmology from an Akaike Information Criterion (AIC)
perspective. This indicates that a broad class of models can account for the
$z<sim 1$ expansion history.
