Swiss Cheese and a Cheesy CMB

TL;DR

This paper investigates Swiss-Cheese cosmological models and demonstrates that large holes significantly affect the CMB, ruling out such models, while smaller holes can mimic Dark Energy in specific directions with low probability.

Contribution

It shows that Swiss-Cheese models with holes larger than 35 Mpc are incompatible with CMB observations, and clarifies the conditions under which smaller holes can mimic Dark Energy.

Findings

Large holes (>35 Mpc) are ruled out by CMB data.

Small holes can mimic Dark Energy in specific directions.

Probability of observing supernova suppression in random directions is very low.

Abstract

It has been argued that the Swiss-Cheese cosmology can mimic Dark Energy, when it comes to the observed luminosity distance-redshift relation. Besides the fact that this effect tends to disappear on average over random directions, we show in this work that based on the Rees-Sciama effect on the cosmic microwave background (CMB), the Swiss-Cheese model can be ruled out if all holes have a radius larger than about 35 Mpc. We also show that for smaller holes, the CMB is not observably affected, and that the small holes can still mimic Dark Energy, albeit in special directions, as opposed to previous conclusions in the literature. However, in this limit, the probability of looking in a special direction where the luminosity of supernovae is sufficiently supressed becomes very small, at least in the case of a lattice of spherical holes considered in this paper.