Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/1151

Title

On the reliability of initial conditions for dissipationless cosmological simulations

Author(s)

Dominguez, Alvaro;  Knebe, Alexander

Abstract

We present the study of ten random realisations of a density field characterised by a cosmological power spectrum P(k) at redshift z=50. The reliability of such initial conditions for N-body simulations is tested with respect to their correlation properties. The power spectrum P(k) and the mass variance σM(r) do not show detectable deviations from the desired behaviour in the intermediate range of scales between the mean interparticle distance and the simulation volume. The estimator for ξ(r) is too noisy to detect any reliable signal at the initial redshift z=50. The particle distributions are then evolved forward until z=0. This allows us to explore the cosmic variance stemming from the random nature of the initial conditions. With cosmic variance we mean the fact that a simulation represents a single realisation of the stochastic initial conditions whereas the real Universe contains many realisations of regions of the size of the box; this problem affects most importantly the scales at about the fundamental mode. We study morphological descriptors of the matter distribution such as the genus, as well as the internal properties of the largest object(s) forming in the box. We find that the scatter is at least comparable to the scatter in the fundamental mode.

Publication type

Journal article

Research centre

Swinburne University of Technology. School of Biophysical Science and Electrical Engineering

Source

Publications of the Astronomical Society of Australia, Vol. 20, no. 2 (2003), pp. 173-183

Publication year

2003

Keyword(s)

methods: N-body simulations;  dark matter

Publisher

CSIRO Publishing

Format

pp. 173-183

ISSN

1323-3580

Publisher URL

http://dx.doi.org/10.1071/AS02039

Copyright

© 2003 Astronomical Society of Australia.

Peer reviewed