Initial Conditions for Large Cosmological Simulations

TL;DR

This paper introduces a software package for generating initial conditions for large-scale cosmological simulations, supporting high resolutions and constrained realizations, with validation up to 4096^3 resolution.

Contribution

It generalizes existing software for distributed architectures and offers a flexible alternative for zoom initial conditions in cosmological simulations.

Findings

Validated up to 4096^3 resolution

Used for large hydrodynamical and dark matter simulations

Supports constrained realizations for specific structures

Abstract

This technical paper describes a software package that was designed to produce initial conditions for large cosmological simulations in the context of the Horizon collaboration. These tools generalize E. Bertschinger's Grafic1 software to distributed parallel architectures and offer a flexible alternative to the Grafic2 software for ``zoom'' initial conditions, at the price of large cumulated cpu and memory usage. The codes have been validated up to resolutions of 4096^3 and were used to generate the initial conditions of large hydrodynamical and dark matter simulations. They also provide means to generate constrained realisations for the purpose of generating initial conditions compatible with, e.g. the local group, or the SDSS catalog.