Cosmology in One Dimension: Vlasov Dynamics

TL;DR

This paper demonstrates that one-dimensional Vlasov simulations can accurately model the fractal properties of an expanding universe, overcoming limitations of traditional N-body methods especially in low-density regions.

Contribution

It introduces one-dimensional Vlasov simulations for cosmology, providing higher accuracy in low-density regions compared to N-body simulations.

Findings

Vlasov simulations confirm N-body results in high-density regions.

Vlasov approach extends reliable modeling to low-density regions.

Demonstrates advantages of phase space meshing over particle sampling.

Abstract

Numerical simulations of self-gravitating systems are generally based on N-body codes, which solve the equations of motion of a large number of interacting particles. This approach suffers from poor statistical sampling in regions of low density. In contrast, Vlasov codes, by meshing the entire phase space, can reach higher accuracy irrespective of the density. Here, we performed one-dimensional Vlasov simulations of a long-standing cosmological problem, namely the fractal properties of an expanding Einstein-de Sitter universe in Newtonian gravity. The N-body results were confirmed for high-density regions and extended to regions of low matter density, where the N-body approach usually fails.