N-body simulations in modified Newtonian dynamics

TL;DR

This paper presents results from N-body simulations in modified Newtonian dynamics (MOND), highlighting fundamental differences in dynamical processes compared to Newtonian gravity with dark matter, such as longer relaxation times and more effective dynamical friction.

Contribution

It introduces the N-MODY simulation code and demonstrates key differences in galaxy dynamics under MOND versus dark matter-based Newtonian gravity.

Findings

Violent relaxation takes longer in MOND.

Galaxy merging is slower in MOND.

Dynamical friction is more effective in MOND.

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.