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/R_{ H})^3 (where L is the size of one patch, and R_{ H} 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 \cite{ BMN} to try to fit the SN curve without dark energy) by making contact with cosmological perturbation theory.
Categories: astro-ph gr-qc hep-th