'Swiss cheese' universe challenges dark energy

This is surely interesting, if theoretically confirmed.

One thing though, the New Scientists article is somewhat misleading - like so many journalistic articles, IMO.

It states: "They allowed the density of matter within each hole to vary with radius and found that in certain cases, photons travelling through under-dense voids had their wavelengths stretched, mimicking dark energy."

This is sort-of true, but what it really says is that this may explain the apparent accelerating expansion without actually needing accelerating expansion. Dark energy causes accelerating expansion, so the voids are not mimicking dark energy! They may simply give another explanation for the dimness of the distant supernovae. This may mean we can fall back to a ΛCDM cosmology with Λ=0, or at least with a much smaller value than presently needed to fit observations.

One problem that this may give rise to is: we will then need a lot more dark matter in order to make the universe appear as close to flat as is observed.

Jorrie

Well Jorrie, it looks like you shot that cheesy theory full of holes! Anyway, I find it hard to believe that the observable universe is much different than any other part.