The MillenniumTNG Project: inferring cosmology from galaxy clustering with accelerated N-body scaling and subhalo abundance matching

Contreras, Sergio; Angulo, Raul E; Springel, Volker; White, Simon D M; Hadzhiyska, Boryana; Hernquist, Lars; Pakmor, Rüdiger; Kannan, Rahul; Hernández-Aguayo, César; Barrera, Monica; Ferlito, Fulvio; Delgado, Ana Maria; Bose, Sownak; Frenk, Carlos

Abstract

We introduce a novel technique for constraining cosmological parameters and galaxy assembly bias using non-linear redshift-space clustering of galaxies. We scale cosmological N-body simulations and insert galaxies with the SubHalo Abundance Matching extended (SHAMe) empirical model to generate over 175 000 clustering measurements spanning all relevant cosmological and SHAMe parameter values. We then build an emulator capable of reproducing the projected galaxy correlation function at the monopole, quadrupole, and hexadecapole level for separations between
and
⁠. We test this approach by using the emulator and Monte Carlo Markov Chain (MCMC) inference to jointly estimate cosmology and assembly bias parameters both for the MTNG740 hydrodynamic simulation and for a semi-analytical model (SAM) galaxy formation built on the MTNG740-DM dark matter-only simulation, obtaining unbiased results for all cosmological parameters. For instance, for MTNG740 and a galaxy number density of
⁠, we obtain
and
(which are within 0.4 and 0.2σ of the MTNG cosmology). For fixed Hubble parameter (h), the constraint becomes
⁠. Our method performs similarly well for the SAM and for other tested sample densities. We almost always recover the true amount of galaxy assembly bias within 1σ. The best constraints are obtained when scales smaller than
are included, as well as when at least the projected correlation function and the monopole are incorporated. These methods offer a powerful way to constrain cosmological parameters using galaxy surveys.

Citation

Contreras, S., Angulo, R. E., Springel, V., White, S. D. M., Hadzhiyska, B., Hernquist, L., Pakmor, R., Kannan, R., Hernández-Aguayo, C., Barrera, M., Ferlito, F., Delgado, A. M., Bose, S., & Frenk, C. (2023). The MillenniumTNG Project: inferring cosmology from galaxy clustering with accelerated N-body scaling and subhalo abundance matching. Monthly Notices of the Royal Astronomical Society, 524(2), 2489-2506. https://doi.org/10.1093/mnras/stac3699

• Journal Article Type: Article
• Acceptance Date: Dec 13, 2022
• Online Publication Date: Jul 20, 2023
• Publication Date: 2023-09
• Deposit Date: Jan 24, 2024
• Publicly Available Date: Jan 24, 2024
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 524
• Issue: 2
• Pages: 2489-2506
• DOI: https://doi.org/10.1093/mnras/stac3699
• Keywords: Space and Planetary Science; Astronomy and Astrophysics
• Public URL: https://durham-repository.worktribe.com/output/2163199