Probing dark energy models with extreme pairwise velocities of galaxy clusters from the DEUS-FUR simulations

Understand

Observations of colliding galaxy clusters with high relative velocity probe the tail of the halo pairwise velocity distribution with the potential of providing a powerful test of cosmology.

• As an example it has been argued that the discovery of the Bullet Cluster challenges standard $\Lambda$CDM model predictions.
• Halo catalogs from N-body simulations have been used to estimate the probability of Bullet-like clusters.
• However, due to simulation volume effects previous studies had to rely on a Gaussian extrapolation of the pairwise velocity distribution to high velocities.