The HalfDome Multi-Survey Cosmological Simulations: N-body Simulations

TL;DR

This paper introduces the HalfDome N-body cosmological simulations designed for joint analysis of upcoming large-scale surveys, providing extensive mock data to aid in understanding dark energy, neutrino mass, and inflation.

Contribution

It presents a large-scale, high-resolution set of cosmological N-body simulations with publicly available data tailored for multi-survey analysis.

Findings

Simulations include full-sky lightcones and halo catalogs up to z=4.

Evolved over 6144^3 particles in a 3.75 h^{-1} Gpc box.

Data supports analysis of key cosmological parameters.

Abstract

Upcoming cosmological surveys have the potential to reach groundbreaking discoveries on multiple fronts, including the neutrino mass, dark energy, and inflation. Most of the key science goals require the joint analysis of datasets from multiple surveys to break parameter degeneracies and calibrate systematics. To realize such analyses, a large set of mock simulations that realistically model correlated observables is required. In this paper we present the N-body component of the HalfDome cosmological simulations, designed for the joint analysis of Stage-IV cosmological surveys, such as Rubin LSST, Euclid, SPHEREx, Roman, DESI, PFS, Simons Observatory, CMB-S4, and LiteBIRD. Our 300TB initial data release includes full-sky lightcones and halo catalogs between $z$=0--4 for 11 fixed cosmology realizations, as well as an additional run with local primordial non-Gaussianity ($f_{\rm NL}$=20). The simulations evolve $6144^3$ particles in a 3.75$\,h^{-1} {\rm Gpc}$ box, reaching a minimum halo mass of $\sim 6 \times 10^{12}\,h^{-1} M_\odot$ and maximum scale of $k \sim 1\,h{\rm Mpc}^{-1}$. Our data is publicly available: instructions to access the data and plans for future data releases can be found at https://halfdomesims.github.io.