Studying large-scale structure probes of modified gravity with COLA

Abstract

We study the effect of two Modified Gravity (MG) theories, $f(R)$ and nDGP, on three probes of large-scale structure, the real space power spectrum estimator $Q_0$, bispectrum and voids, and validate fast approximate COLA simulations against full $N$-body simulations for the prediction of these probes. We find that using the first three even multipoles of the redshift space power spectrum to estimate $Q_0$ is enough to reproduce the MG boost factors of the real space power spectrum for both halo and galaxy catalogues. By analysing the bispectrum and reduced bispectrum of Dark Matter (DM), we show that the strong MG signal present in the DM bispectrum is mainly due to the enhanced power spectrum. We warn about adopting screening approximations in simulations as this neglects non-linear contributions that can source a significant component of the MG bispectrum signal at the DM level, but we argue that this is not a problem for the bispectrum of galaxies in redshift space where the signal is dominated by the non-linear galaxy bias. Finally, we perform void-finding on our galaxy mock catalogues by the ZOBOV watershed algorithm. To apply a linear model for Redshift-Space Distortion (RSD) in the void-galaxy cross-correlation function, we first examine the effects of MG on the void profiles entering into the RSD model. We find relevant MG signals in the integrated-density, velocity dispersion and radial velocity profiles in the nDGP theory. Fitting the RSD model for the linear growth rate, we recover the linear theory prediction in an nDGP model, which is larger than the $\Lambda$CDM prediction at the $3\sigma$ level. In $f(R)$ theory we cannot naively compare the results of the fit with the linear theory prediction as this is scale-dependent, but we obtain results that are consistent with the $\Lambda$CDM prediction.

26+6 pages, 19 figures, 3 tables - Accepted for publication in JCAP

References in corpus (15)

• The Confrontation between General Relativity and Experiment
• Models of f(R) Cosmic Acceleration that Evade Solar-System Tests
• Beyond the Cosmological Standard Model
• Galaxy Evolution from Halo Occupation Distribution Modeling of DEEP2 and SDSS Galaxy Clustering
• ZOBOV: a parameter-free void-finding algorithm
• The Aspen--Amsterdam Void Finder Comparison Project
• Constraining $M_{\nu }$ with the Bispectrum II: The Total Information Content of the Galaxy Bispectrum
• Cosmic voids in modified gravity models with massive neutrinos
• Cosmological constraints without fingers of God
• A Fast Route to Non-Linear Clustering Statistics in Modified Gravity Theories
• Creating Jackknife and Bootstrap estimates of the covariance matrix for the two-point correlation function
• Enabling matter power spectrum emulation in beyond-$\Lambda$CDM cosmologies with COLA
• Fast generation of mock galaxy catalogues in modified gravity models with COLA
• Velocity profiles of matter and biased tracers around voids
• Fingerprints of modified gravity on galaxies in voids

Cited by in corpus (15)

• Why Cosmic Voids Matter: Nonlinear Structure & Linear Dynamics
• $\text{Hi-COLA}$: Fast, approximate simulations of structure formation in Horndeski gravity
• Euclid: Cosmology forecasts from the void-galaxy cross-correlation function with reconstruction
• The void-galaxy cross-correlation function with massive neutrinos and modified gravity
• Dynamic cosmography of the local Universe: Laniakea and five more watershed superclusters
• Sesame: A power spectrum emulator pipeline for beyond-$\Lambda$CDM models
• Revisiting Vainshtein Screening for fast N-body simulations
• Primordial Black Hole-Neutron Star Merger Rate in Modified Gravity
• Challenges in Constraining Gravity with Cosmic Voids
• A field-level emulator for modified gravity
• Alcock-Paczyński effect on void-finding: Implications for void-galaxy cross-correlation modelling
• Fast simulation mapping: from standard to modified gravity cosmologies using the bias assignment method
• Fast Generation of Weak Lensing Maps in Modified Gravity with COLA
• Dark energy constraints in light of theoretical priors
• Individual halo bias in models of $f(R)$ gravity