Multiparticle collision simulations of dense stellar systems and plasmas

TL;DR

This paper introduces a novel Multi-particle collision (MPC) simulation technique for dense stellar systems and plasmas, offering computational efficiency and conservation properties, as an alternative to traditional methods.

Contribution

The paper presents the MPC method for simulating collisional dynamics, which scales more efficiently and conserves physical quantities better than existing approaches.

Findings

MPC scales with N log N, faster than N^2 for direct N-body.

MPC accurately models collisional relaxation effects.

The method conserves energy and momentum rigorously.

Abstract

We summarize a series of numerical experiments of collisional dynamics in dense stellar systems such as globular clusters (GCs) and in weakly collisional plasmas using a novel simulation technique, the so-called Multi-particle collision (MPC) method, alternative to Fokker-Planck and Monte Carlo approaches. MPC is related to particle-mesh approaches for the computation of self consistent long-range fields, ensuring that simulation time scales with $N\log N$ in the number of particles, as opposed to $N^2$ for direct $N$-body. The collisional relaxation effects are modelled by computing particle interactions based on a collision operator approach that ensures rigorous conservation of energy and momenta and depends only on particles velocities and cell-based integrated quantities.