# How to Simulate the Universe in a Computer

@article{Knebe2004HowTS, title={How to Simulate the Universe in a Computer}, author={Alexander Knebe}, journal={Publications of the Astronomical Society of Australia}, year={2004}, volume={22}, pages={184 - 189} }

Abstract In this contribution a broad overview of the methodologies of cosmological N-body simulations and a short introduction explaining the general idea behind such simulations is presented. After explaining how to set up the initial conditions using a set of N particles two (diverse) techniques are presented for evolving these particles forward in time under the influence of their self-gravity. One technique (tree codes) is solely based upon a sophistication of the direct particle–particle…

## 5 Citations

### How to simulate the Universe in a box? Testing modified gravity with a N-body simulation code.

- Physics
- 2008

In this paper we present preliminary results from cosmological simulations of modified gravity in the dark matter sector. Our results show improvements over standard cold dark matter cosmology. The…

### Constraints on alternative cosmological models from clustering and redshift-space distortions

- Physics
- 2019

In this Thesis I have exploited the most recent observational data from CMB, BAO and growth rate of LSS as well as N-body simulations of modified gravity, to investigate the spatial properties of the…

### Disc heating: comparing the Milky Way with cosmological simulations

- Physics
- 2010

We present an analysis of a suite of simulations run with different particle- and grid-based cosmological hydrodynamical codes and compare them with observational data of the Milky Way. This is the…

### Massive Neutrinos and Galaxy Clustering in f(R) Gravity Cosmologies

- PhysicsProgress in Fine Particle Plasmas
- 2020

Cosmic neutrinos have been playing a key role in cosmology since the discovery of their mass. They can affect cosmological observables and have several implications being the only hot dark matter…

### Foreword: Gravity Workshop 2004

- PhysicsPublications of the Astronomical Society of Australia
- 2005

Gravity 2004 was organized by the Australian National Institute for TheoreticalAstrophysics (ANITA) and hosted by the University of Sydney on the 15th and 16th of April, 2004. The goal of Gravity…

## 21 References

### Numerical techniques for large cosmological N-body simulations

- Physics
- 1985

Techniques for carrying out large N-body simulations of the gravitational evolution of clustering in the fundamental cube of an infinite periodic universe are described and compared. The accuracy of…

### N-body simulations with perturbation particles – I. Method and tests

- Physics
- 1993

Conventional N-body simulations are not well suited to the study of perturbed stellar systems because the perturbations under study have to compete with non-negligible particle noise. If an exact…

### Multi‐level adaptive particle mesh (MLAPM): a c code for cosmological simulations

- Physics
- 2001

We present a computer code written in c that is designed to simulate structure formation from collisionless matter. The code is purely grid-based and uses a recursively refined Cartesian grid to…

### SIMULATIONS OF STRUCTURE FORMATION IN THE UNIVERSE

- Physics
- 1998

Cosmic structure has formed as a result of gravitational amplification of primordial density fluctuations together with the action of other physical processes (adiabatic gas dynamics, radiative…

### The Santa Barbara Cluster Comparison Project: A Comparison of Cosmological Hydrodynamics Solutions

- Physics
- 1999

We have simulated the formation of an X-ray cluster in a cold dark matter universe using 12 different codes. The codes span the range of numerical techniques and implementations currently in use,…

### GADGET: a code for collisionless and gasdynamical cosmological simulations

- Physics, Computer Science
- 2001

### Two-body relaxation in cosmological simulations

- Physics
- 2002

It is logically possible that early two-body relaxation in simulations of cosmological clustering influences the final structure of massive clusters. Convergence studies in which mass and spatial…

### Tree Particle-Mesh: An Adaptive, Efficient, and Parallel Code for Collisionless Cosmological Simulation

- Computer Science, Physics
- 2003

An improved implementation of an N-body code for simulating collisionless cosmological dynamics is presented and is compared to P3M and a tree code and is found to give equivalent results in significantly less time.

### The inner structure of ΛCDM haloes – I. A numerical convergence study

- Physics
- 2002

We present a comprehensive set of convergence tests which explore the role of various numerical parameters on the equilibrium structure of a simulated dark matter halo. We report results obtained…

### The evolution of substructure - I. A new identification method

- Physics
- 2004

We describe our new 'MLAPM halo finder' (MHF), which is based on the adaptive grid structure of the N-body code MLAPM. We then extend the MHF code in order to track the orbital evolution of…