Fast full N-body simulations of generic modified gravity: conformal coupling models

Ruan, Cheng-Zong; Hernández-Aguayo, César; Li, Baojiu; Arnold, Christian; Baugh, Carlton M.; Klypin, Anatoly; Prada, Francisco

doi:10.48550/arxiv.2110.00328

Cited by 4 publications

(16 citation statements)

References 131 publications

(196 reference statements)

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“…Several codes exist that simulate various kinds of modified gravity (Oyaizu 2008;Schmidt 2009;Zhao et al 2011;Li et al 2012a;Brax et al 2012;Li et al 2013a,b;Puchwein et al 2013;Arnold et al 2019;Ruan et al 2021;Hernández-Aguayo et al 2021), usually extending well-established GR codes such as RAMSES, Gadget, and AREPO. carried out a comparison of various N -body codes for f (R), DGP, and Symmetron models by simulating a L = 250h −1 Mpc box with N = 512 3 particles.…”

Section: Modified Gravitymentioning

confidence: 99%

Large-scale dark matter simulations

Angulo,

Hahn

2021

Preprint

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We review the field of collisionless numerical simulations for the large-scale structure of the Universe. We start by providing the main set of equations solved by these simulations and their connection with General Relativity. We then recap the relevant numerical approaches: discretization of the phase-space distribution (focusing on N -body but including alternatives, e.g., Lagrangian submanifold and Schrödinger-Poisson) and the respective techniques for their time evolution and force calculation (Direct summation, mesh techniques, and hierarchical tree methods). We pay attention to the creation of initial conditions and the connection with Lagrangian Perturbation Theory. We then discuss the possible alternatives in terms of the micro-physical properties of dark matter (e.g., neutralinos, warm dark matter, QCD axions, Bose-Einstein condensates, and primordial black holes), and extensions to account for multiple fluids (baryons and neutrinos), primordial non-Gaussianity and modified gravity. We continue by discussing challenges involved in achieving highly accurate predictions. A key aspect of cosmological simulations is the connection to cosmological observables, we discuss various techniques in this regard: structure finding, galaxy formation and baryonic modelling, the creation of emulators and light-cones, and the role of machine learning. We finalise with a recount of state-of-the-art large-scale simulations and conclude with an outlook for the next decade.

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Section: Modified Gravitymentioning

confidence: 99%

Large-scale dark matter simulations

Angulo,

Hahn

2021

Preprint

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“…In the main body of this paper, the simulations are run with (Klypin & Prada 2018) (for ΛCDM) and its modified gravity extension, - (Hernández-Aguayo et al 2021a;Ruan et al 2021) for all the MG models.…”

Section: N -Body Simulationsmentioning

confidence: 99%

“…extends to a general class of modified gravity theories by adding extra modules for solving MG scalar field equations. In the code papers of -(Hernández-Aguayo et al 2021a; Ruan et al 2021), we describe the optimised multigrid relaxation algorithm used to solve the non-linear MG equations, such as Eq. ( 6) and Eq.…”

Section: N -Body Simulationsmentioning

confidence: 99%

“…The simulations follow the evolution of 1024 3 dark matter particles in a simulation box with a side L box = 512 h −1 Mpc, starting at an initial redshift of zinit = 100 with the initial conditions (ICs) generated using the Zel'dovich approximation. For further details of these simulations see Hernández-Aguayo et al (2021a); Ruan et al (2021).…”

Section: N -Body Simulationsmentioning

confidence: 99%

“…Thanks to significant recent progress, modern MG Nbody codes are now capable of running large-volume and highresolution simulations to meet the requirements of upcoming wide field galaxy surveys. We test the validity of the ST distribution using N -body simulations, based on the newly-developed MG code - (Hernández-Aguayo et al 2021a;Ruan et al 2021), which enables the fast generation of simulations in a wide range of MG models.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Towards an accurate model of small-scale redshift-space distortions in modified gravity

Ruan,

Cuesta-Lazaro,

Eggemeier

et al. 2021

Preprint

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The coming generation of galaxy surveys will provide measurements of galaxy clustering with unprecedented accuracy and data size, which will allow us to test cosmological models at much higher precision than achievable previously. This means that we must have more accurate theoretical predictions to compare with future observational data. As a first step towards more accurate modelling of the redshift space distortions (RSD) of small-scale galaxy clustering in modified gravity (MG) cosmologies, we investigate the validity of the so-called Skew-T (ST) probability distribution function (PDF) of halo pairwise peculiar velocities in these models. We show that, combined with the streaming model of RSD, the ST PDF substantially improves the small-scale predictions by incorporating skewness and kurtosis, for both ΛCDM and two leading MG models: f (R) gravity and the DGP braneworld model. The ST model reproduces the velocity PDF and redshift-space halo clustering measured from MG N -body simulations very well down to ∼ 5 h −1 Mpc. In particular, we investigate the enhancements of halo pairwise velocity moments with respect to ΛCDM for a larger range of MG variants than previous works, and present simple explanations to the behaviours observed. By performing a simple Fisher analysis, we find a significnat increase in constraining power to detect modifications of General Relativity by introducing small-scale information in the RSD analyses.

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Fast full N-body simulations of generic modified gravity: derivative coupling models

Hernández‐Aguayo

Ruan

et al. 2022

J. Cosmol. Astropart. Phys.

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We present mg-glam, a code developed for the very fast production of full N-body cosmological simulations in modified gravity (MG) models. We describe the implementation, numerical tests and first results of a large suite of cosmological simulations for two broad classes of MG models with derivative coupling terms — the Vainshtein- and Kmouflage-type models — which respectively features the Vainshtein and Kmouflage screening mechanism. Derived from the parallel particle-mesh code glam, mg-glam incorporates an efficient multigrid relaxation technique to solve the characteristic nonlinear partial differential equations of these models. For Kmouflage, we have proposed a new algorithm for the relaxation solver, and run the first simulations of the model to understand its cosmological behaviour. In a companion paper, we describe versions of this code developed for conformally-coupled MG models, including several variants of f(R) gravity, the symmetron model and coupled quintessence. Altogether, mg-glam has so far implemented the prototypes for most MG models of interest, and is broad and versatile. The code is highly optimised, with a tremendous (over two orders of magnitude) speedup when comparing its running time with earlier N-body codes, while still giving accurate predictions of the matter power spectrum and dark matter halo abundance. mg-glam is ideal for the generation of large numbers of MG simulations that can be used in the construction of mock galaxy catalogues and accurate emulators for ongoing and future galaxy surveys.

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Fast full N-body simulations of generic modified gravity: conformal coupling models

Cited by 4 publications

References 131 publications

Large-scale dark matter simulations

Large-scale dark matter simulations

Towards an accurate model of small-scale redshift-space distortions in modified gravity

Fast full N-body simulations of generic modified gravity: derivative coupling models

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