‘Swiss-cheese’ inhomogeneous cosmology and the dark energy problem

We study an exact swiss-cheese model of the Universe, where inhomogeneous LTB patches are embedded in a flat FLRW background, in order to see how observations of distant sources are affected. We find negligible integrated effect, suppressed by (L/R₇) ³ (where L is the size of one patch, and R₇ is the Hubble radius), both perturbatively and non-perturbatively. We disentangle this effect from the Doppler term (which is much larger and has been used recently to try to fit the SN curve without dark energy) by making contact with cosmological perturbation theory.