Stirring N-body systems: Universality of end states

TL;DR

This study investigates how collisionless N-body systems evolve under repeated perturbations, revealing a universal end state independent of initial conditions and gravitational models, including Newtonian and MOND.

Contribution

It demonstrates the robustness of a universal attractor in N-body systems' phase-space evolution across different perturbation schemes and gravitational paradigms.

Findings

Convergence towards a limited solution group regardless of initial conditions.

Identification of perturbations leading to radial orbit instability (ROI).

Universality of the end state under various circumstances.

Abstract

We study the evolution of the phase-space of collisionless N-body systems under repeated stirrings or perturbations. We find convergence towards a limited solution group, in accordance with Hansen 2010, that is independent of the initial system and environmental conditions, paying particular attention to the assumed gravitational paradigm (Newtonian and MOND). We examine the effects of changes to the perturbation scheme and in doing so identify a large group of perturbations featuring radial orbit instability (ROI) which always lead to convergence. The attractor is thus found to be a robust and reproducible effect under a variety of circumstances.