Gravitational entropy of cosmic expansion

We apply a recent proposal to define "gravitational entropy" to the expansion of cosmic voids within the framework of non-perturbative General Relativity. By considering CDM void configurations compatible with basic observational constraints, we show that this entropy grows from post-inflationary conditions towards a final asymptotic value in a late time fully non-linear regime described by the Lemaitre-Tolman-Bondi (LTB) dust models. A qualitatively analogous behavior occurs if we assume a positive cosmological constant consistent with a $\Lambda$-CDM background model. However, the $\Lambda$ term introduces a significant suppression of entropy growth with the terminal equilibrium value reached at a much faster rate.
Comment: 5 Pages, 2 figures, AN style. Contribution to Proceedings of the Second Caribbean Symposium on Nuclear and Astroparticle Physics (STARS 2013), La Habana, Cuba, 5-9 May 2013