Remapping dark matter halo catalogues between cosmological simulations

TL;DR

This paper introduces a fast method to modify dark matter halo catalogues from one cosmological simulation to resemble those from a different cosmology, enabling rapid generation of diverse mock galaxy samples.

Contribution

It extends existing rescaling techniques by working directly with halo catalogues, allowing internal structure modifications without needing full particle data.

Findings

Successfully rescaled a matter-only simulation to a LCDM model with BAO features.

Demonstrated the method's ability to modify halo properties efficiently.

Provides a foundation for rapid, flexible mock galaxy catalogue generation.

Abstract

We present and test a method for modifying the catalogue of dark matter haloes produced from a given cosmological simulation, so that it resembles the result of a simulation with an entirely different set of parameters. This extends the method of Angulo & White (2010), which rescales the full particle distribution from a simulation. Working directly with the halo catalogue offers an advantage in speed, and also allows modifications of the internal structure of the haloes to account for nonlinear differences between cosmologies. Our method can be used directly on a halo catalogue in a self contained manner without any additional information about the overall density field: although the large-scale displacement field is required by the method, this can be inferred from the halo catalogue alone. We show proof of concept of our method by rescaling a matter-only simulation with no baryon acoustic oscillation (BAO) features to a more standard LCDM model containing a cosmological constant and a BAO signal. In conjunction with the halo occupation approach, this method provides a basis for the rapid generation of mock galaxy samples spanning a wide range of cosmological parameters.