We present an analytically solvable nonlinear model of structure formation in a Universe with only dust. The model is an LTB solution (of General Relativity) and structures are shells of different density. We show that the luminosity distance-redshift relation has significant corrections at low redshift when the density contrast becomes nonlinear. A minimal effect is a correction in apparent magnitudes of order 0.15. We discuss different possibilities that could further enhance this effect and mimick Dark Energy.
Categories: astro-ph gr-qc hep-th