Cluster number counts dependence on dark energy inhomogeneities and coupling to dark matter

Cluster number counts can be used to test dark energy models. We investigate dark energy candidates which are coupled to dark matter. We analyse the cluster number counts dependence on the amount of dark matter coupled to dark energy. Furthermore, we study how dark energy inhomogeneities affect cluster abundances. It is shown that increasing the coupling reduces significantly the cluster number counts, and that dark energy inhomogeneities increases cluster abundances. Wiggles in cluster number counts are shown to be a specific signature of coupled dark energy models. Future observations could possibly detect such oscillations and discriminate among the different dark energy models. © 2006 RAS.