Can dark energy explain the observed outflow in galaxy clusters?
  Recent observations of the Virgo cluster and the Local Group suggested that some galaxies are flowing out from their parent cluster. This may be the signature that dark energy (DE) acts significantly also on small cosmological scales. By means of direct N-body simulations we performed several simulations, in which the effect of DE and gravity are taken into account, aiming to determine whether DE can produce an outflow of galaxies compatible with observations. Comparing the different simulations, our results suggest that the observed outflow of galaxies is likely due to the local effect of DE. 
M. Donnari, M. Arca-Sedda, M. Merafina
astro-ph.CO astro-ph.GA