Skewness of matter distribution in clustering dark energy cosmologies
  We calculate the skewness (the third moment $S_3$) of matter distribution in
dynamical dark energy cosmologies. We pay particular attention to the impact of
dark energy perturbations on this quantity. There is indeed a clear signature
of dark energy perturbations on this quantity. By properly allowing dark energy
perturbations we show that their impact on $S_3$ is strong enough (a factor
$\sim 3$ greater) to easily discriminate between clustering and non-clustering
dark energy cosmologies. This indicates that high order statistics of the
cosmic density field are useful to the study of dark energy models and are
potentially able to rule out clustering dark energy cosmologies.
