Supernovae observations in a “meatball” universe with a local void

We study the impact of cosmic inhomogeneities on the interpretation of observations. We build an inhomogeneous universe model without dark energy that can confront supernova data and yet is reasonably well compatible with the Copernican principle. Our model combines a relatively small local void, that gives apparent acceleration at low redshifts, with a meatball model that gives sizable lensing (dimming) at high redshifts. Together these two elements, which focus on different effects of voids on the data, allow the model to mimic the concordance model.

Figure 1

The larger disks represent the meatballs of the family $A$, while the smaller ones represent the meatballs of the family $B$. The concentric circles mark the overdense shells in the LTB bubble and are roughly $100h^{-1}\mathrm{Mpc}$ apart.

Figure 2

Top: The 307 SNe of the union compilation of Ref. 9 binned with $\Delta z=0.1$. Bottom: Shift in the distance modulus $\Delta m$ for $N_O$ taken from the top panel and for the meatball model of this paper.

Figure 3

$\Delta H_r/H$ (top panel) and density contrast (bottom panel) with respect to normalized proper distance [$R/a(t)$] at times corresponding to the redshifts indicated in the plot.

Figure 4

Top panel: Shown is the distance modulus with respect to the empty universe for the inhomogeneous model of this paper, for the $\Lambda \mathrm{CDM}$ model and for the EdS model together with the full union compilation of Ref. 9. Bottom panel: Zoom for low redshifts.