AI-assisted super-resolution cosmological simulations II: Halo substructures, velocities and higher order statistics

TL;DR

This paper presents a super-resolution model that enhances low-resolution cosmological simulations to produce high-resolution matter distributions, accurately capturing small-scale structures, velocities, and higher order statistics, thus enabling detailed galaxy formation modeling.

Contribution

The study introduces an advanced super-resolution model capable of generating high-resolution cosmological data from low-resolution inputs, including phase-space information and substructures, validated across multiple statistical measures.

Findings

SR model matches high-resolution power spectra at percent level

Generated small-scale structures are visually authentic and statistically consistent

Model accurately reproduces halo properties and velocity distributions

Abstract

In this work, we expand and test the capabilities of our recently developed super-resolution (SR) model to generate high-resolution (HR) realizations of the full phase-space matter distribution, including both displacement and velocity, from computationally cheap low-resolution (LR) cosmological N-body simulations. The SR model enhances the simulation resolution by generating 512 times more tracer particles, extending into the deeply non-linear regime where complex structure formation processes take place. We validate the SR model by deploying the model in 10 test simulations of box size 100 Mpc/h, and examine the matter power spectra, bispectra and 2D power spectra in redshift space. We find the generated SR field matches the true HR result at percent level down to scales of k ~ 10 h/Mpc. We also identify and inspect dark matter halos and their substructures. Our SR model generate visually authentic small-scale structures, that cannot be resolved by the LR input, and are in good statistical agreement with the real HR results. The SR model performs satisfactorily on the halo occupation distribution, halo correlations in both real and redshift space, and the pairwise velocity distribution, matching the HR results with comparable scatter, thus demonstrating its potential in making mock halo catalogs. The SR technique can be a powerful and promising tool for modelling small-scale galaxy formation physics in large cosmological volumes.