Dynamics of Galaxies in Clusters
  Recent observations by the Hubble Space Telescope suggest that a strong dynamical and morphological evolution of disk galaxies has occurred in clusters of galaxies. I present the result of the self-consistent high-resolution simulations of galactc dynamics in the three cosmologically formed clusters. The disks of large galaxies survive but thicken by a factor of two and cease new star formation. The dark matter halos are truncated in agreement with analytical models. The overall effect is the morphological transformation of spirals into S0 galaxies. 
Oleg Y. Gnedin (Princeton)