papers.bib

@ARTICLE{10.1093/mnras/stab2484,
    author = {Maksimova, Nina A and Garrison, Lehman H and Eisenstein, Daniel J and Hadzhiyska, Boryana and Bose, Sownak and Satterthwaite, Thomas P},
    title = "{AbacusSummit: a massive set of high-accuracy, high-resolution N-body simulations}",
    journal = {Monthly Notices of the Royal Astronomical Society},
    volume = {508},
    number = {3},
    pages = {4017-4037},
    year = {2021},
    month = {09},
    abstract = "{We present the public data release of the AbacusSummit cosmological N-body simulation suite, produced with the Abacus N-body code on the Summit supercomputer of the Oak Ridge Leadership Computing Facility. Abacus achieves \\$\\mathcal \\{O\\}(10^\\{-5\\})\\$ median fractional force error at superlative speeds, calculating 70M particle updates per second per node at early times, and 45M particle updates per second per node at late times. The simulation suite totals roughly 60 trillion particles, the core of which is a set of 139 simulations with particle mass \\$2\\times 10^\\{9\\}\\, h^\\{-1\\}\\, \\mathrm\\{M\\}\_\\odot\\$ in box size \\$2\\, h^\\{-1\\}\\, \\mathrm\\{Gpc\\}\\$. The suite spans 97 cosmological models, including Planck 2018, previous flagship simulation cosmologies, and a linear derivative and cosmic emulator grid. A subsuite of 1883 boxes of size \\$500\\, h^\\{-1\\}\\, \\mathrm\\{Mpc\\}\\$ is available for covariance estimation. AbacusSummit data products span 33 epochs from z = 8 to 0.1 and include light cones, full particle snapshots, halo catalogues, and particle subsets sampled consistently across redshift. AbacusSummit is the largest high-accuracy cosmological N-body data set produced to date.}",
    issn = {0035-8711},
    doi = {10.1093/mnras/stab2484},
    url = {https://doi.org/10.1093/mnras/stab2484},
    eprint = {https://academic.oup.com/mnras/article-pdf/508/3/4017/40811763/stab2484.pdf},
}


@ARTICLE{10.1093/mnras/stab2482,
    author = {Garrison, Lehman H and Eisenstein, Daniel J and Ferrer, Douglas and Maksimova, Nina A and Pinto, Philip A},
    title = "{The abacus cosmological N-body code}",
    journal = {Monthly Notices of the Royal Astronomical Society},
    volume = {508},
    number = {1},
    pages = {575-596},
    year = {2021},
    month = {09},
    abstract = "{We present abacus, a fast and accurate cosmological N-body code based on a new method for calculating the gravitational potential from a static multipole mesh. The method analytically separates the near- and far-field forces, reducing the former to direct 1/r2 summation and the latter to a discrete convolution over multipoles. The method achieves 70 million particle updates per second per node of the Summit supercomputer, while maintaining a median fractional force error of 10−5. We express the simulation time-step as an event-driven ‘pipeline’, incorporating asynchronous events such as completion of co-processor work, input/output, and network communication. abacus has been used to produce the largest suite of N-body simulations to date, the abacussummit suite of 60 trillion particles, incorporating on-the-fly halo finding. abacus enables the production of mock catalogues of the volume and resolution required by the coming generation of cosmological surveys.}",
    issn = {0035-8711},
    doi = {10.1093/mnras/stab2482},
    url = {https://doi.org/10.1093/mnras/stab2482},
    eprint = {https://academic.oup.com/mnras/article-pdf/508/1/575/40458823/stab2482.pdf},
}


@ARTICLE{10.1093/mnras/stab2980,
    author = {Hadzhiyska, Boryana and Eisenstein, Daniel and Bose, Sownak and Garrison, Lehman H and Maksimova, Nina},
    title = "{CompaSO: A new halo finder for competitive assignment to spherical overdensities}",
    journal = {Monthly Notices of the Royal Astronomical Society},
    year = {2021},
    month = {10},
    abstract = "{We describe a new method (CompaSO) for identifying groups of particles in cosmological N-body simulations. CompaSO builds upon existing spherical overdensity (SO) algorithms by taking into consideration the tidal radius around a smaller halo before competitively assigning halo membership to the particles. In this way, the CompaSO finder allows for more effective deblending of haloes in close proximity as well as the formation of new haloes on the outskirts of larger ones. This halo-finding algorithm is used in the AbacusSummit suite of N-body simulations, designed to meet the cosmological simulation requirements of the Dark Energy Spectroscopic Instrument (DESI) survey. CompaSO is developed as a highly efficient on-the-fly group finder, which is crucial for enabling good load-balancing between the GPU and CPU and the creation of high-resolution merger trees. In this paper, we describe the halo-finding procedure and its particular implementation in Abacus, accompanying it with a qualitative analysis of the finder. We test the robustness of the CompaSO catalogues before and after applying the cleaning method described in an accompanying paper and demonstrate its effectiveness by comparing it with other validation techniques. We then visualise the haloes and their density profiles, finding that they are well fit by the NFW formalism. Finally, we compare other properties such as radius-mass relationships and two-point correlation functions with that of another widely used halo finder, rockstar.}",
    issn = {0035-8711},
    doi = {10.1093/mnras/stab2980},
    url = {https://doi.org/10.1093/mnras/stab2980},
    note = {stab2980},
    eprint = {https://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stab2980/40751402/stab2980.pdf},
}


@ARTICLE{10.1093/mnras/stab3066,
    author = {Hadzhiyska, Boryana and Garrison, Lehman H and Eisenstein, Daniel and Bose, Sownak},
    title = "{The halo light cone catalogues of AbacusSummit}",
    journal = {Monthly Notices of the Royal Astronomical Society},
    year = {2021},
    month = {10},
    abstract = "{We describe a method for generating halo catalogues on the light cone using the AbacusSummit suite of N-body simulations. The main application of these catalogues is the construction of realistic mock galaxy catalogues and weak lensing maps on the sky. Our algorithm associates the haloes from a set of coarsely-spaced snapshots with their positions at the time of light-cone crossing by matching halo particles to on-the-fly light cone particles. It then records the halo and particle information into an easily accessible product, which we call the AbacusSummit halo light cone catalogues. Our recommended use of this product is in the halo mass regime of Mhalo \\> 2.1 × 1011 M⊙/h for the base resolution simulations, i.e. haloes containing at least 100 particles, where the interpolated halo properties are most reliable. To test the validity of the obtained catalogues, we perform various visual inspections and consistency checks. In particular, we construct galaxy mock catalogues of emission-line galaxies (ELGs) at z ∼ 1 by adopting a modified version of the AbacusHOD script, which builds on the standard halo occupation distribution (HOD) method by including various extensions. We find that the multipoles of the auto-correlation function are consistent with the predictions from the full-box snapshot, implicitly validating our algorithm. In addition, we compute and output CMB convergence maps and find that the auto- and cross-power spectrum agrees with the theoretical prediction at the subpercent level. Halo light cone catalogues for 25 base and 2 huge simulations at the fiducial cosmology is available at DOI:10.13139/OLCF/1825069}",
    issn = {0035-8711},
    doi = {10.1093/mnras/stab3066},
    url = {https://doi.org/10.1093/mnras/stab3066},
    note = {stab3066},
    eprint = {https://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stab3066/40820763/stab3066.pdf},
}


@article{10.1093/mnras/stac555,
    author = {Bose, Sownak and Eisenstein, Daniel J and Hadzhiyska, Boryana and Garrison, Lehman H and Yuan, Sihan},
    title = "{Constructing high-fidelity halo merger trees in abacussummit}",
    journal = {Monthly Notices of the Royal Astronomical Society},
    volume = {512},
    number = {1},
    pages = {837-854},
    year = {2022},
    month = {03},
    abstract = "{Tracking the formation and evolution of dark matter haloes is a critical aspect of any analysis of cosmological N-body simulations. In particular, the mass assembly of a halo and its progenitors, encapsulated in the form of its merger tree, serves as a fundamental input for constructing semi-analytic models of galaxy formation and, more generally, for building mock catalogues that emulate galaxy surveys. We present an algorithm for constructing halo merger trees from abacussummit, the largest suite of cosmological N-body simulations performed to date consisting of nearly 60 trillion particles, and which has been designed to meet the Cosmological Simulation Requirements of the Dark Energy Spectroscopic Instrument (DESI) survey. Our method tracks the cores of haloes to determine associations between objects across multiple time slices, yielding lists of halo progenitors and descendants for the several tens of billions of haloes identified across the entire suite. We present an application of these merger trees as a means to enhance the fidelity of abacussummit halo catalogues by flagging and ‘merging’ haloes deemed to exhibit non-monotonic past merger histories. We show that this cleaning technique identifies portions of the halo population that have been deblended due to choices made by the halo finder, but which could have feasibly been part of larger aggregate systems. We demonstrate that by cleaning halo catalogues in this post-processing step, we remove potentially unphysical features in the default halo catalogues, leaving behind a more robust halo population that can be used to create highly accurate mock galaxy realizations from abacussummit.}",
    issn = {0035-8711},
    doi = {10.1093/mnras/stac555},
    url = {https://doi.org/10.1093/mnras/stac555},
    eprint = {https://academic.oup.com/mnras/article-pdf/512/1/837/42996773/stac555.pdf},
}


@article{10.1093/mnras/stab3355,
    author = {Yuan, Sihan and Garrison, Lehman H and Hadzhiyska, Boryana and Bose, Sownak and Eisenstein, Daniel J},
    title = "{AbacusHOD: a highly efficient extended multitracer HOD framework and its application to BOSS and eBOSS data}",
    journal = {Monthly Notices of the Royal Astronomical Society},
    volume = {510},
    number = {3},
    pages = {3301-3320},
    year = {2021},
    month = {11},
    abstract = "{We introduce the AbacusHOD model and present two applications of AbacusHOD and the AbacusSummit simulations to observations. AbacusHOD is a Halo Occupation Distribution (HOD) framework written in Python that is particle-based, multitracer, highly generalized, and highly efficient. It is designed specifically with multitracer/cosmology analyses for next-generation large-scale structure surveys in mind, and takes advantage of the volume and precision offered by the new state-of-the-art AbacusSummit cosmological simulations. The model is also highly customizable and should be broadly applicable to any upcoming surveys and a diverse range of cosmological analyses. In this paper, we demonstrate the capabilities of the AbacusHOD framework through two example applications. The first example demonstrates the high efficiency and the large HOD extension feature set through an analysis of full-shape redshift-space clustering of BOSS galaxies at intermediate to small scales (\\$\\lt 30\\, h^\\{-1\\}\\$ Mpc), assessing the necessity of introducing secondary galaxy biases (assembly bias). We find strong evidence for using halo environment instead of concentration to trace secondary galaxy bias, a result which also leads to a moderate reduction in the ‘lensing is low’ tension. The second example demonstrates the multitracer capabilities of the AbacusHOD package through an analysis of the extended Baryon Oscillation Spectroscopic Survey cross-correlation measurements between three different galaxy tracers: luminous red galaxies, emission-line galaxies, and quasi-stellar objects. We expect the AbacusHOD framework, in combination with the AbacusSummit simulation suite, to play an important role in a simulation-based analysis of the upcoming Dark Energy Spectroscopic Instrument data sets.}",
    issn = {0035-8711},
    doi = {10.1093/mnras/stab3355},
    url = {https://doi.org/10.1093/mnras/stab3355},
    eprint = {https://academic.oup.com/mnras/article-pdf/510/3/3301/42147651/stab3355.pdf},
}


@ARTICLE{2019MNRAS.485.3370G,
       author = {{Garrison}, Lehman H. and {Eisenstein}, Daniel J. and {Pinto}, Philip A.},
        title = "{A high-fidelity realization of the Euclid code comparison N-body simulation with ABACUS}",
      journal = {\mnras},
     keywords = {methods: numerical, large-scale structure of universe, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Computational Physics},
         year = 2019,
        month = may,
       volume = {485},
       number = {3},
        pages = {3370-3377},
          doi = {10.1093/mnras/stz634},
archivePrefix = {arXiv},
       eprint = {1810.02916},
 primaryClass = {astro-ph.CO},
       adsurl = {https://ui.adsabs.harvard.edu/abs/2019MNRAS.485.3370G},
      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}

@ARTICLE{2018ApJS..236...43G,
       author = {{Garrison}, Lehman H. and {Eisenstein}, Daniel J. and {Ferrer}, Douglas and
         {Tinker}, Jeremy L. and {Pinto}, Philip A. and {Weinberg}, David H.},
        title = "{The Abacus Cosmos: A Suite of Cosmological N-body Simulations}",
      journal = {\apjs},
     keywords = {large-scale structure of universe, methods: numerical, Astrophysics - Cosmology and Nongalactic Astrophysics},
         year = 2018,
        month = jun,
       volume = {236},
       number = {2},
          eid = {43},
        pages = {43},
          doi = {10.3847/1538-4365/aabfd3},
archivePrefix = {arXiv},
       eprint = {1712.05768},
 primaryClass = {astro-ph.CO},
       adsurl = {https://ui.adsabs.harvard.edu/abs/2018ApJS..236...43G},
      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}


@ARTICLE{2016MNRAS.461.4125G,
       author = {{Garrison}, Lehman H. and {Eisenstein}, Daniel J. and {Ferrer}, Douglas and
         {Metchnik}, Marc V. and {Pinto}, Philip A.},
        title = "{Improving initial conditions for cosmological N-body simulations}",
      journal = {\mnras},
     keywords = {methods: numerical, galaxies: haloes, large-scale structure of Universe, Astrophysics - Cosmology and Nongalactic Astrophysics},
         year = 2016,
        month = oct,
       volume = {461},
       number = {4},
        pages = {4125-4145},
          doi = {10.1093/mnras/stw1594},
archivePrefix = {arXiv},
       eprint = {1605.02333},
 primaryClass = {astro-ph.CO},
       adsurl = {https://ui.adsabs.harvard.edu/abs/2016MNRAS.461.4125G},
      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}


@PHDTHESIS{2009PhDT.......175M,
       author = {{Metchnik}, Marc Victor Leonard},
        title = "{A fast N-body scheme for computational cosmology}",
       school = {The University of Arizona},
         year = 2009,
        month = jan,
       adsurl = {https://ui.adsabs.harvard.edu/abs/2009PhDT.......175M},
      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}

  
@article{10.1093/mnras/staa3434,
    author = {Joyce, Michael and Garrison, Lehman and Eisenstein, Daniel},
    title = "{Quantifying resolution in cosmological N-body simulations using self-similarity}",
    journal = {Monthly Notices of the Royal Astronomical Society},
    volume = {501},
    number = {4},
    pages = {5051-5063},
    year = {2020},
    month = {11},
    abstract = "{We demonstrate that testing for self-similarity in scale-free simulations provides an excellent tool to quantify the resolution at small scales of cosmological N-body simulations. Analysing two-point correlation functions measured in simulations using abacus , we show how observed deviations from self-similarity reveal the range of time and distance scales in which convergence is obtained. While the well-converged scales show accuracy below 1 per cent, our results show that, with a small force softening length, the spatial resolution is essentially determined by the mass resolution. At later times, the lower cut-off scale on convergence evolves in comoving units as a−1/2 (a being the scale factor), consistent with a hypothesis that it is set by two-body collisionality. A corollary of our results is that N-body simulations, particularly at high red-shift, contain a significant spatial range in which clustering appears converged with respect to the time-stepping and force softening but has not actually converged to the physical continuum result. The method developed can be applied to determine the resolution of any clustering statistic and extended to infer resolution limits for non-scale-free simulations.}",
    issn = {0035-8711},
    doi = {10.1093/mnras/staa3434},
    url = {https://doi.org/10.1093/mnras/staa3434},
    eprint = {https://academic.oup.com/mnras/article-pdf/501/4/5051/35926462/staa3434.pdf},
}


@article{10.1093/mnras/stab1096,
    author = {Garrison, Lehman H and Joyce, Michael and Eisenstein, Daniel J},
    title = "{Good and proper: self-similarity of N-body simulations with proper force softening}",
    journal = {Monthly Notices of the Royal Astronomical Society},
    volume = {504},
    number = {3},
    pages = {3550-3560},
    year = {2021},
    month = {04},
    abstract = "{Analysis of self-similarity in scale-free N-body simulations reveals the spatial and temporal scales for which statistics measured in cosmological simulations are converged to the physical continuum limit. We examine how the range of scales in which the two-point correlation function is converged depends on the force softening length and whether it is held constant in comoving or proper coordinates. We find that a proper softening that reaches roughly 1/30th of the inter-particle spacing by the end of the simulation resolves the same spatial and temporal scales as a comoving softening of the same length while using a third fewer time-steps, for a range of scale factors typical to Lambda cold dark matter (ΛCDM) simulations. We additionally infer an inherent resolution limit, set by the particle mass and scaling as a−1/2, beyond which reducing the softening does not improve the resolution. We postulate a mapping of these results with spectral index n = −2 to ΛCDM simulations.}",
    issn = {0035-8711},
    doi = {10.1093/mnras/stab1096},
    url = {https://doi.org/10.1093/mnras/stab1096},
    eprint = {https://academic.oup.com/mnras/article-pdf/504/3/3550/37888807/stab1096.pdf},
}


@article{10.1093/mnras/stac578,
    author = {Maleubre, Sara and Eisenstein, Daniel and Garrison, Lehman H and Joyce, Michael},
    title = "{Accuracy of power spectra in dissipationless cosmological simulations}",
    journal = {Monthly Notices of the Royal Astronomical Society},
    volume = {512},
    number = {2},
    pages = {1829-1842},
    year = {2022},
    month = {03},
    abstract = "{We exploit a suite of large N-body simulations (up to N = 40963) performed with abacus, of scale-free models with a range of spectral indices n, to better understand and quantify convergence of the matter power spectrum. Using self-similarity to identify converged regions, we show that the maximal wavenumber resolved at a given level of accuracy increases monotonically as a function of time. At 1 per cent level it starts at early times from a fraction of \\$k\_\\Lambda\\$, the Nyquist wavenumber of the initial grid, and reaches at most, if the force softening is sufficiently small, \\$\\{\\sim\\}2\\{-\\}3 k\_\\Lambda\\$ at the very latest times we evolve to. At the \\$5\\{\\{\\ \\rm per\\ cent\\}\\}\\$ level, accuracy extends up to wavenumbers of order \\$5k\_\\Lambda\\$ at late times. Expressed as a suitable function of the scale-factor, accuracy shows a very simple n-dependence, allowing a extrapolation to place conservative bounds on the accuracy of N-body simulations of non-scale-free models like LCDM. We note that deviations due to discretization in the converged range are not well modelled by shot noise, and subtracting it in fact degrades accuracy. Quantitatively our findings are broadly in line with the conservative assumptions about resolution adopted by recent studies using large cosmological simulations (e.g. Euclid Flagship) aiming to constrain the mildly non-linear regime. On the other hand, we remark that conclusions about small-scale clustering (e.g. concerning the validity of stable clustering) obtained using PS data at wavenumbers larger than a few \\$k\_\\Lambda\\$ may need revision in light of our convergence analysis.}",
    issn = {0035-8711},
    doi = {10.1093/mnras/stac578},
    url = {https://doi.org/10.1093/mnras/stac578},
    eprint = {https://academic.oup.com/mnras/article-pdf/512/2/1829/43026623/stac578.pdf},
}


@article{10.1093/mnras/stab3160,
    author = {Garrison, Lehman H and Abel, Tom and Eisenstein, Daniel J},
    title = "{Self-similarity of k-nearest neighbour distributions in scale-free simulations}",
    journal = {Monthly Notices of the Royal Astronomical Society},
    volume = {509},
    number = {2},
    pages = {2281-2288},
    year = {2021},
    month = {10},
    abstract = "{We use the k-nearest neighbour probability distribution function (kNN-PDF; Banerjee \\& Abel 2021a) to assess convergence in a scale-free N-body simulation. Compared to our previous two-point analysis, the kNN-PDF allows us to quantify our results in the language of haloes and numbers of particles, while also incorporating non-Gaussian information. We find good convergence for 32 particles and greater at densities typical of haloes, while 16 particles and fewer appear unconverged. Halving the softening length extends convergence to higher densities, but not to fewer particles. Our analysis is less sensitive to voids, but we analyse a limited range of underdensities and find evidence for convergence at 16 particles and greater even in sparse voids.}",
    issn = {0035-8711},
    doi = {10.1093/mnras/stab3160},
    url = {https://doi.org/10.1093/mnras/stab3160},
    eprint = {https://academic.oup.com/mnras/article-pdf/509/2/2281/41199811/stab3160.pdf},
}