Modelling galaxy clustering in redshift space with a Lagrangian bias formalism and $N$-body simulations

Abstract

Improving the theoretical description of galaxy clustering on small scales is an important challenge in cosmology, as it can considerably increase the scientific return of forthcoming galaxy surveys -- e.g. tightening the bounds on neutrino masses and deviations from general relativity. In this paper, we propose and test a new model for the clustering of galaxies that is able to accurately describe redshift-space distortions even down to small scales. This model corresponds to a second-order perturbative Lagrangian bias expansion which is advected to Eulerian space employing a displacement field extracted from $N$-body simulations. Eulerian coordinates are then transformed into redshift space by directly employing simulated velocity fields augmented with nuisance parameters capturing various possible satellite fractions and intra-halo small-scale velocities. We quantify the accuracy of our approach against samples of physically-motivated mock galaxies selected according to either Stellar Mass (SM) or Star Formation Rate (SFR) at multiple abundances and at $z=0$ and $1$. We find our model describes the monopole, quadrupole, and hexadecapole of the galaxy-power spectra down to scales of $k\approx 0.6[h/$Mpc] within the accuracy of our simulations. This approach could pave the way to significantly increase the amount of cosmological information to be extracted from future galaxy surveys.

15 pages, 8 figures

References in corpus (8)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in Fourier-space
• Modelling redshift space distortions in hierarchical cosmologies
• Full-shape cosmology analysis of SDSS-III BOSS galaxy power spectrum using emulator-based halo model: a $5\%$ determination of ${\sigma }_8$
• The Gaussian streaming model and Lagrangian effective field theory
• Simulations and symmetries
• The galaxy-halo connection of emission-line galaxies in IllustrisTNG
• The bias of dark matter tracers: assessing the accuracy of mapping techniques

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• The Bacco Simulation Project: Bacco Hybrid Lagrangian Bias Expansion Model in Redshift Space
• A Parameter-Masked Mock Data Challenge for Beyond-Two-Point Galaxy Clustering Statistics
• COMET: Clustering Observables Modelled by Emulated perturbation Theory
• HYMALAIA: A Hybrid Lagrangian Model for Intrinsic Alignments
• Statistics of biased tracers in variance-suppressed simulations
• Gaussian Lagrangian Galaxy Bias
• Probabilistic Lagrangian bias estimators and the cumulant bias expansion
• Aemulus $\nu$: Precision halo mass functions in w$\nu$CDM cosmologies
• Inference of matter power spectrum at z=0 using DESI DR1 Full-Shape data
• Emulating galaxy and peculiar velocity clustering on non-linear scales