Moment-preserving particle merging via non-negative least squares
Computational Physics
2026-04-02 v1 Fluid Dynamics
Plasma Physics
Abstract
A novel particle merging algorithm for rarefied gas dynamics simulations is proposed that can conserve arbitrary velocity and spatial moments of the particle distribution via solving a non-negative least squares problem. An extension that preserves both exact and approximate collision rates is also derived. The algorithm is applied to the simulation of several model rarefied gas dynamics problems, where it exhibits noticeably lower merging-induced error in key macroscopic quantities.
Keywords
Cite
@article{arxiv.2604.00668,
title = {Moment-preserving particle merging via non-negative least squares},
author = {Georgii Oblapenko and Manuel Torrilhon},
journal= {arXiv preprint arXiv:2604.00668},
year = {2026}
}