N-body simulations in modified Newtonian dynamics

¹ Astronomy Department, University of Bologna, via Ranzani 1, 40127 Bologna, Italy
² INAF-Bologna Astronomical Observatory, via Ranzani 1, 40127 Bologna, Italy

Abstract

We describe some results obtained with N-MODY, a code for N-body simulations of collisionless stellar systems in modified Newtonian dynamics (MOND). We found that a few fundamental dynamical processes are profoundly different in MOND and in Newtonian gravity with dark matter. In particular, violent relaxation, phase mixing and galaxy merging take significantly longer in MOND than in Newtonian gravity, while dynamical friction is more effective in a MOND system than in an equivalent Newtonian system with dark matter.