Tidal forces acting on galaxies in clusters lead to a strong dynamical evolution .
In order to quantify the amount of evolution , I run self-consistent N -body simulations of disk galaxies for a variety of models in the hierarchically forming clusters .
The tidal field along the galactic orbits is extracted from the simulations of cluster formation in the \Omega _ { 0 } = 1 ; \Omega _ { 0 } = 0.4 ; and \Omega _ { 0 } = 0.4 , \Omega _ { \Lambda } = 0.6 cosmological scenarios .
For large spiral galaxies with the rotation speed of 250 km s ^ { -1 } , tidal interactions truncate massive dark matter halos at 30 \pm 6 kpc , and thicken stellar disks by a factor 2 to 3 , increasing Toomre ’ s parameter to Q \gtrsim 2 and halting star formation .
Low density galaxies , such as the dwarf spheroidals with the circular velocity of 20 km s ^ { -1 } and the extended low surface brightness galaxies with the scale length of 10 - 15 kpc , are completely disrupted by tidal shocks .
Their debris contribute to the diffuse intracluster light .
The tidal effects are significant not only in the core but throughout the cluster and can be parametrized by the critical tidal density .
The tidally-induced evolution results in the transformation of the infalling spirals into S0 galaxies and in the depletion of the LSB population .
In the low \Omega _ { 0 } cosmological models , clusters form earlier and produce stronger evolution of galaxies .