Szekeres Swiss-Cheese model and supernova observations

TL;DR

This paper investigates whether inhomogeneous Szekeres Swiss-cheese models can explain supernova Ia dimming, finding that large-scale structures are needed, and highlighting limitations of axial symmetry assumptions.

Contribution

It introduces the use of axially symmetric Szekeres Swiss-cheese models for supernova dimming analysis, comparing results with Lemaître-Tolman models and discussing the implications.

Findings

Small scale inhomogeneities (~50 Mpc) cannot fully explain supernova dimming.

Structures of order 500 Mpc or larger are required to fit the data.

Axial symmetry assumptions may influence the results.

Abstract

We use different particular classes of axially symmetric Szekeres Swiss-cheese models for the study of the apparent dimming of the supernovae of type Ia. We compare the results with those obtained in the corresponding Lemaitre-Tolman Swiss-cheese models. Although the quantitative picture is different the qualitative results are comparable, i.e, one cannot fully explain the dimming of the supernovae using small scale ~50 Mpc inhomogeneities. To fit successfully the data we need structures of order of 500 Mpc size or larger. However, this result might be an artifact due to the use of axial light rays in axially symmetric models. Anyhow, this work is a first step in trying to use Szekeres Swiss-cheese models in cosmology and it will be followed by the study of more physical models with still less symmetry.