Voids and overdensities of coupled Dark Energy

Abstract

We investigate the clustering properties of dynamical Dark Energy even in association of a possible coupling between Dark Energy and Dark Matter. We find that within matter inhomogeneities, Dark Energy migth form voids as well as overdensity depending on how its background energy density evolves. Consequently and contrarily to what expected, Dark Energy fluctuations are found to be slightly suppressed if a coupling with Dark Matter is permitted. When considering density contrasts and scales typical of superclusters, voids and supervoids, perturbations amplitudes range from $|\delta_\phi|\sim {\cal O} (10^{-6})$ to $|\delta_\phi|\sim {\cal O} (10^{-4})$ indicating an almost homogeneous Dark Energy component.