Simulation techniques for cosmological simulations

TL;DR

This paper reviews various simulation techniques used in cosmology, including N-body, particle-mesh, hybrid methods, and hydrodynamic codes, highlighting their advantages and limitations for modeling large scale structures.

Contribution

It provides a comprehensive overview of current cosmological simulation methods, emphasizing their strengths and weaknesses for accurate large scale structure modeling.

Findings

Comparison of N-body and hydrodynamic methods

Discussion of hybrid and grid-based techniques

Identification of current challenges in simulation accuracy

Abstract

Modern cosmological observations allow us to study in great detail the evolution and history of the large scale structure hierarchy. The fundamental problem of accurate constraints on the cosmological parameters, within a given cosmological model, requires precise modelling of the observed structure. In this paper we briefly review the current most effective techniques of large scale structure simulations, emphasising both their advantages and shortcomings. Starting with basics of the direct N-body simulations appropriate to modelling cold dark matter evolution, we then discuss the direct-sum technique GRAPE, particle-mesh (PM) and hybrid methods, combining the PM and the tree algorithms. Simulations of baryonic matter in the Universe often use hydrodynamic codes based on both particle methods that discretise mass, and grid-based methods. We briefly describe Eulerian grid methods, and also some variants of Lagrangian smoothed particle hydrodynamics (SPH) methods.