High-z massive clusters as a test for dynamical coupled dark energy
  The recent detection (Jee etal 2009) of the massive cluster XMMU J2235.3-2557
at a redshift z = 1.4, with an estimated mass M = 6.4 +- 1.2 X 10^14 M_sol, has
been claimed to be a possible challenge to the standard LCDM cosmological
model. More specifically, the probability to detect such a cluster has been
estimated to be 0.005 if a LCDM model with gaussian initial conditions is
assumed, resulting in a 3 sigma discrepancy from the standard cosmological
model. In this paper we propose to use high redshift clusters as the one
detected in Jee etal 2009 to compare the cosmological constant scenario with
interacting dark energy models. We show that coupled dark energy models, where
an interaction is present between dark energy and cold dark matter, can
significantly enhance the probability to observe very massive clusters at high
redshift.
