在广义相对论以及修正引力的f（R）和Wavelon模型的背景下，我们使用了一个球形模型和一个扩展的漂移集形式主义（extended excursion set formalism with driving diffusive barriers）来预测宇宙空洞的丰度。我们检测球形空洞从一套N体模拟这些引力理论和比较测得的空洞丰度理论预测。我们发现，我们的模型正确地描述了丰富的暗物质和星系空洞，提供了一个更好的拟合比以前的建议，在文献中的基础上静态障碍。我们使用模拟丰度结果来拟合丰度模型自由参数作为修改后的重力参数的函数，并表明暗物质空隙的计数可以提供有趣的约束修改后的重力。对于星系空洞，更密切相关的光学观测，我们发现，约束修改重力从空洞丰度单独可能是更具挑战性的。在目前和即将进行的星系调查的背景下，空洞和晕统计数据，包括其丰度，配置文件和相关性的组合，应有效地区分显示不同的筛选机制的修改后的重力模型。
英文摘要：
We use a spherical model and an extended excursion set formalism with drifting diffusive barriers to predict the abundance of cosmic voids in the context of general relativity as well as f(R) and symmetron models of modified gravity. We detect spherical voids from a suite of N-body simulations of these gravity theories and compare the measured void abundance to theory predictions. We find that our model correctly describes the abundance of both dark matter and galaxy voids, providing a better fit than previous proposals in the literature based on static barriers. We use the simulation abundance results to fit for the abundance model free parameters as a function of modified gravity parameters, and show that counts of dark matter voids can provide interesting constraints on modified gravity. For galaxy voids, more closely related to optical observations, we find that constraining modified gravity from void abundance alone may be significantly more challenging. In the context of current and upcoming galaxy surveys, the combination of void and halo statistics including their abundances, profiles and correlations should be effective in distinguishing modified gravity models that display different screening mechanisms.
We apply our tetrad-based approach for constructing spherically-symmetric solutions in general relativity to modelling a void, and compare it with the standard Lemaître-Tolman-Bondi (LTB) formalism. In particular, we construct models for the void observed in the direction of Draco in the WISE-2MASS galaxy survey, and a corresponding cosmic microwave background (CMB) temperature decrement in the Planck data in the same direction. We find that the present-day density and velocity profiles of the void are not well constrained by the existing data, so that void models produced from the two approac…
Combining galaxy cluster and void abundances is a novel, powerful way to constrain deviations from General Relativity and the $Λ$CDM model. For a flat $w$CDM model with growth of large-scale structure parameterized by the redshift-dependent growth index $γ(z) = γ_0 + γ_1 z/(1+z)$ of linear matter perturbations, combining void and cluster abundances in future surveys with Euclid and the 4-metre Multi-Object Spectroscopic Telescope (4MOST) could improve the Figure of Merit for ($w, γ_0, γ_1$) by a factor of 20 compared to individual abundances. In an ideal case, improvement on current cosmologic…
The abundance of voids and the excursion set formalism
我们提出了一系列的N体模拟的ΛCDM宇宙学的暗物质分布的空洞的数量密度的测量。我们将空洞定义为密度极小值周围ρ v = 0.2ρ m的球形区域，以便将我们的结果与使用偏移集形式主义预测的丰度相关联。利用球形演化模型中δ v =-2.7的线性欠密度，我们发现在从线性到非线性的映射中不守恒数密度的体积守恒模型，在空隙半径1< r（Mpc/h）<15的范围内，与测量的丰度匹配在16%以内。这个模型固定了宇宙在空洞中的体积分数，并假设当相似大小的空洞膨胀1.7倍时，它们会合并，从而达到今天的非线性密度ρ_v = 0.2ρ_m。我们发现Sheth & van de Weygaert（2004）的空洞数密度模型在相同尺度范围内大大高估了丰度。我们发现，体积守恒模型能很好地匹配在较高红移z=0.5和1下模拟测量的空洞数密度，并能正确地预测物质主导的Ω_m = 1宇宙的丰度，误差在25%以内。我们检查了晕分布中的空隙丰度，发现与暗物质相比，较小的空隙（r<10 Mpc/h）较少，而较大的空隙（r>10 Mpc/h）较多。这些结果表明，在晕或星系分布中确定的空洞与暗物质中的潜在空洞分布以复杂的方式相关，如果空洞被用作宇宙学的精确探针，则值得进一步研究。
We present a sample of 66 galaxies belonging to the equatorial part (Dec.= -7$^o$, +7$^o$) of the large so called Eridanus void (after Fairall 1998). The void galaxies are selected as to be separated from the luminous galaxies ($M_{\rm B} < M_{\rm B}^{*} +1$), delineating the void, by more than 2 Mpc. Our main goal is to study systematically the evolutionary parameters of the void sample (metallicity and gas content) and to compare the void galaxy properties with their counterparts residing in denser environments. Besides the general galaxy parameters, compiled mainly from the literature, we p…
Testing the imprint of non-standard cosmologies on void profiles using Monte Carlo random walks
使用蒙特卡罗随机行走的对数正态分布，我们展示了如何定性研究非标准宇宙学的空洞属性。我们将这种方法应用于f（R）修正的重力模型，并恢复（Achitouv et al. 2016）的N体模拟结果，用于空隙轮廓及其与GR的偏差。这种方法可以扩展到研究大尺度结构的其他特性，例如空隙的丰度或过密环境。我们还介绍了一种新的方法来识别宇宙网络中的空隙，只使用随机位置周围的密度波动的几个测量。该算法允许选择具有特定轮廓和半径的空隙。因此，我们可以针对f（R）和标准重力空隙轮廓之间差异较大的空隙类别。最后，我们适用于我们的空标准星系模拟目录，并讨论如何我们的空发现者的灵活性，可以用来减少系统的错误时，探测星系空关联函数的增长率。
Modifications to General Relativity (GR) often incorporate screening mechanisms in order to remain compatible with existing tests of gravity. The screening is less efficient in underdense regions, which suggests that cosmic voids can be a useful cosmological probe for constraining modified gravity models. In particular, weak lensing by voids has been proposed as a promising test of such theories. Usually, voids are identified from galaxy distributions, making them biased tracers of the underlying matter field. An alternative approach is to study voids identified in weak lensing maps -- weak le…
Cosmic voids are progressively emerging as a new viable cosmological probe. Their abundance and density profiles are sensitive to modifications of gravity, as well as to dark energy and neutrinos. The main goal of this work is to investigate the possibility of exploiting cosmic void statistics to disentangle the degeneracies resulting from a proper combination of $f(R)$ modified gravity and neutrino mass. We use N-body simulations to analyse the density profiles and size function of voids traced by both dark matter particles and haloes. We find clear evidence of the enhancement of gravity in $…
Cosmic voids are an important probe of large-scale structure that can constrain cosmological parameters and test cosmological models. We present a new paradigm for void studies: void detection in weak lensing convergence maps. This approach identifies objects that relate directly to our theoretical understanding of voids as underdensities in the total matter field and presents several advantages compared to the customary method of finding voids in the galaxy distribution. We exemplify this approach by identifying voids using the weak lensing peaks as tracers of the large-scale structure. We fi…
We present a systematic comparison of several existing and new void finding algorithms, focusing on their potential power to test a particular class of modified gravity models - chameleon $f(R)$ gravity. These models deviate from standard General Relativity (GR) more strongly in low-density regions and thus voids are a promising venue to test them. We use Halo Occupation Distribution (HOD) prescriptions to populate haloes with galaxies, and tune the HOD parameters such that the galaxy two-point correlation functions are the same in both f(R) and GR models. We identify both 3D voids as well as …
The intrinsic alignments of galaxies, i.e., the correlation between galaxy shapes and their environment, are a major source of contamination for weak gravitational lensing surveys. Most studies of intrinsic alignments have so far focused on measuring and modelling the correlations of luminous red galaxies with galaxy positions or the filaments of the cosmic web. In this work, we investigate alignments around cosmic voids. We measure the intrinsic alignments of luminous red galaxies detected by the Sloan Digital Sky Survey around a sample of voids constructed from those same tracers and with ra…
Modified gravity (MG) theories aim to reproduce the observed acceleration of the Universe by reducing the dark sector while simultaneously recovering General Relativity (GR) within dense environments. Void studies appear to be a suitable scenario to search for imprints of alternative gravity models on cosmological scales. Voids cover an interesting range of density scales where screening mechanisms fade out, which reaches from a density contrast $δ\approx -1$ close to their centers to $δ\approx 0$ close to their boundaries. We present an analysis of the level of distinction between GR and two …
Cosmic voids provide a unique environment to study galaxy formation and evolution. In this paper, we analyse a set of hydrodynamic zoom-in simulations of voids, to analyse in detail their inner structures. These voids were identified in a cosmological simulation and classified according to their surrounding dynamics at very large scales: whether they are in expansion or contraction at their outskirts. We study how these environments and the dynamics of voids impact the baryonic processes inside haloes and their mechanisms of formation and evolution. We find an under-abundance of processed gas …
J-PAS & FLAMINGO: Cosmic voids and void galaxies in the gravitational landscape of photometric surveys
University of Tartu（塔尔图大学）；University of Groningen（格罗宁根大学）；University of Turku（图尔库大学）；Leiden University（莱顿大学）；Universidade de São Paulo（圣保罗大学）；Instituto de Astronomia, Geofísica e Ciências Atmosféricas da USP（圣保罗大学天文、地球物理与大气科学研究所）；Centro de Estudios de Física del Cosmos de Aragón (CEFCA)（阿拉贡宇宙物理研究中心）
Euclid: Measuring the intrinsic alignment of galaxies around cosmic voids in the \Euclid Flagship simulation\
Aix-Marseille Université（艾克斯-马赛大学）；CNRS/IN2P3, CPPM（法国国家科学研究中心/欧洲核子研究组织粒子物理与核物理研究所，普罗旺斯粒子与天体物理中心）；Departament de Física, Universitat Autònoma de Barcelona（巴塞罗那自治大学物理系）；Instituto de Astronomia Teorica y Experimental (IATE-CONICET)（理论与实验天文研究所）；Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology（高能物理研究所，巴塞罗那科学技术学院）；LAM（拉格朗日天体物理实验室）；MTA-CSFK Lendület Large-Scale Structure Research Group, Konkoly-Thege Miklós út 15-17（匈牙利科学院CSFK Lentület大尺度结构研究组）；Konkoly Observatory, HUN-REN CSFK, MTA Centre of Excellence（孔科利天文台）；ELTE Eötvös Loránd University, Institute of Physics and Astronomy（罗兰大学物理与天文学研究所）
The spatial distribution of galaxies and their gravitational lensing signal offer complementary tests of galaxy formation physics and cosmology. However, their synergy can only be fully exploited if both probes are modelled accurately and consistently. In this paper, we demonstrate that this can be achieved using an extension of Subhalo Abundance Matching, dubbed SHAMe. Specifically, we use mock catalogues built from the TNG300 hydrodynamical simulation to show that SHAMe can simultaneously model the multipoles of the redshift-space galaxy correlation function and galaxy-galaxy lensing, withou…
Towards precision cosmology with Voids x CMB correlations (I): Roman-Agora mock catalogs and pipeline validation
Instituto de Astrofísica de Canarias（加那利天体物理学研究所）；Universidad de La Laguna（拉古纳大学）；MTA–CSFK Lendület “Momentum” Large-Scale Structure (LSS) Research Group（马塔-匈牙利科学院技术研究中心“动量”大尺度结构研究组）；Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences（孔科利天文台，匈牙利研究与创新地球与天文学研究中心）；CPPM, Aix-Marseille Université, CNRS/IN2P3（马赛物理中心，艾克斯-马赛大学，法国国家科学研究中心/法国国家核与粒子物理研究所）；Princeton University（普林斯顿大学）
Satellite galaxy abundance dependency on cosmology in Magneticum simulations
Alma Mater Studiorum Università di Bologna（博洛尼亚大学）；INAF - Osservatorio Astronomico di Trieste（意大利国家天体物理研究所的里雅斯特天文台）；IFPU - Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）；University of Trieste（的里雅斯特大学）；INFN - National Institute for Nuclear Physics（意大利国家核物理研究所）；Ludwig-Maximilians-Universität München（慕尼黑大学）；Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理研究所）
