  Dissipationless collapses in Modified Newtonian Dynamics (MOND) have been
studied by using our MOND particle-mesh N-body code, finding that the projected
density profiles of the final virialized systems are well described by Sersic
profiles with index m<4 (down to m~2 for a deep-MOND collapse). The simulations
provided also strong evidence that phase mixing is much less effective in MOND
than in Newtonian gravity. Here we describe "ad hoc" numerical simulations with
the force angular components frozen to zero, thus producing radial collapses.
Our previous findings are confirmed, indicating that possible differences in
radial orbit instability under Newtonian and MOND gravity are not relevant in
the present context.

Astrophysics