Understanding galaxy properties may be the key to unlocking some of the most intriguing mysteries of modern cosmology. Recent work relied on machine learning to extract cosmological constraints on $Ω_\mathrm{m}$ using only one galaxy. But if this is true, how should we select the galaxy to use for cosmology inference? In this paper, we consider selecting a galaxy that lies in cosmic voids, the underdense regions of the cosmic web, and compare the constraints obtained with the ones obtained when randomly selecting a galaxy in the whole sample. We use the IllustrisTNG galaxy catalog from the CAMELS project and the VIDE void finder to identify galaxies inside voids. We show that void galaxies provide stronger constraints on $Ω_\mathrm{m}$ compared to randomly selected galaxies. This result suggests that the distinctive characteristics of void galaxies may provide a cleaner and more effective environment for extracting cosmological information.
Cosmic voids constitute promising cosmological laboratories. However, a full description of all the redshift-space effects that affect observational measurements is mandatory in order to obtain unbiased cosmological constraints. We make a description in a nutshell of these effects and lay the theoretical foundations for designing reliable cosmological tests based on the void size function and the void-galaxy cross-correlation function. We show that modern spectroscopic surveys offer a high signal-to-noise ratio to detect and study them.
We extract void catalogs from the Sloan Digital Sky Survey Data Release 16 (SDSS DR16) survey and also from the Millennium simulation. We focus our comparison on distribution of galaxies brighter than $M_r < -18$ inside voids and study the mean separation of void galaxies, distance from the void center, and the radial density profile. We find that mean separation of void galaxies depends on void size, as bigger voids have lower mean separation in both samples. However, void galaxies in the observation sample seem to have generally larger mean-distance than simulated ones at any given void size…
In this work, we study the cosmological constant problem and Hubble tension in the void-dominated cosmology scenario \cite{Yusofi:2022hgg}. For this goal, we will first consider the cosmic voids in the cosmic web as interconnected ideal spherical bubbles at the early Planck scale and late large scale. By heuristic calculations for each cosmic void, we obtain particular mass density and cosmological constant that are the same order of magnitude as the entire universe on any scale. The values obtained for the cosmological constant vary from scale to scale. As a result, it will be shown that ther…
CSST large-scale structure analysis pipeline: IV. Cosmic Voids Identified from Galaxy Group Samples as Probes of the Large-scale Structure
Shanghai Jiao Tong University(上海交通大学);National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台);University of Chinese Academy of Sciences(UCAS)(中国科学院大学)
Quantifying Environmental Effects on Galaxy Properties using Non-spherical Voids Identified from SDSS DR7
Shanghai Jiao Tong University(上海交通大学);National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台);University of Chinese Academy of Sciences(中国科学院大学)
Max Planck Institute for Extraterrestrial Physics(马克斯·普朗克地外物理研究所);Center for Computational Astrophysics, Flatiron Institute(平顿研究所计算天体物理学中心);ICTP, International Centre for Theoretical Physics(国际理论物理中心)
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 …
Voids may affect galaxy formation via weakening mass infall or increasing disk sizes, which could potentially play a role in the formation of giant low surface brightness galaxies (LSBGs). If a dark matter halo forms at the potential hill corresponding to a void of the cosmic web, which we denote the 'elaphrocentre' in contrast to a barycentre, then the elaphrocentre should weaken the infall rate to the halo when compared to infall rates towards barycentres. We investigate this hypothesis numerically. We present a complete software pipeline to simulate galaxy formation, starting from a power s…
We present GIGANTES, the most extensive and realistic void catalog suite ever released -- containing over 1 billion cosmic voids covering a volume larger than the observable Universe, more than 20 TB of data, and created by running the void finder VIDE on QUIJOTE's halo simulations. The expansive and detailed GIGANTES suite, spanning thousands of cosmological models, opens up the study of voids, answering compelling questions: Do voids carry unique cosmological information? How is this information correlated with galaxy information? Leveraging the large number of voids in the GIGANTES suite, o…
Multiprobe cosmology forecasts from halo-occupation-distribution-based forward modeling of galaxy and void statistics
Steward Observatory, University of Arizona(亚利桑那大学斯图尔德天文台);Department of Physics, University of Arizona(亚利桑那大学物理系);Aix-Marseille Université, CNRS/IN2P3, CPPM(艾克斯-马赛大学,法国国家科学研究中心/法国国家核子和粒子物理研究所,粒子与宇宙学中心);Department of Astrophysical Sciences, Peyton Hall, Princeton University(普林斯顿大学天体物理学系);Universitäts-Sternwarte München, Fakultät für Physik, Ludwig-Maximilians-Universität(慕尼黑大学天文台,慕尼黑大学物理学院)
We measure the void probability function (VPF) of galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS). The VPF provides complementary information to standard two-point statistics in that it is sensitive to galaxy bias in the most extreme underdensities in the cosmic web. Thus the VPF is ideal for testing whether halo occupation of galaxies depends on large-scale density, an effect known as galaxy assembly bias. We find that standard HOD model---one parameterized by halo mass only---fit only to the two-point function, accurately predicts the VPF. Additionally, for HOD models where de…
Towards precision cosmology with Void x CMB correlations (II): Impact of mock catalogs on the Void x CMB lensing signal
Instituto de Astrofísica de Canarias(加那利群岛天体物理研究所);Universidad de La Laguna(拉戈纳大学);MTA–CSFK Lendület “Momentum” Large-Scale Structure (LSS) Research Group(匈牙利科学院-塞格德大学“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,匈牙利研究与创新网络地球与天文学研究中心);CPPM, Aix-Marseille Université, CNRS/IN2P3(地中海粒子与核物理中心,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);California Institute of Technology(加州理工学院)
研究通过分析模拟目录对Void x CMB引力透镜信号的影响,探讨了未来宇宙学约束的潜力,发现该信号对模拟目录的依赖性较低,预计罗马任务结合现有和未来CMB观测将显著提高信号噪声比。
Using a mapping from dark matter halos to galaxy properties based on hydrodynamical simulations, we explore the impact of galaxy properties on the void size function and the void-galaxy correlation function. We replicate the properties of galaxies from Illustris on MassiveNus halos, to perform both luminosity and star formation rate cuts on MassiveNus halos. We compare the impact of such cuts on voids properties with respect to cuts on halo mass (as usually performed on halo catalogs driven from N-body simulations). We find that void catalogs built from luminosity-selected galaxies and halos a…
We report novel cosmological constraints obtained from cosmic voids in the final BOSS DR12 dataset. They arise from the joint analysis of geometric and dynamic distortions of average void shapes (i.e., the stacked void-galaxy cross-correlation function) in redshift space. Our model uses tomographic deprojection to infer real-space void profiles and self-consistently accounts for the Alcock-Paczynski (AP) effect and redshift-space distortions (RSD) without any prior assumptions on cosmology or structure formation. It is derived from first physical principles and provides an extremely good descr…
Upcoming surveys such as \LSST{} and \Euclid{} will significantly improve the power of weak lensing as a cosmological probe. To maximise the information that can be extracted from these surveys, it is important to explore novel statistics that complement standard weak lensing statistics such as the shear-shear correlation function and peak counts. In this work, we use a recently proposed weak lensing observable -- weak lensing voids -- to make parameter constraint forecasts for an LSST-like survey. We use the \cosmoslics{} $w$CDM simulation suite to measure void statistics as a function of cos…
Consistency of the growth rate in different environments with the 6dF Galaxy Survey: measurement of the void-galaxy and galaxy-galaxy correlation functions
Barren but not Empty: The Impact of Void Environments on Galaxy and Halo Populations
Ludwig-Maximilians Universität München(慕尼黑大学);Swinburne University of Technology(斯威本科技大学);University of Nottingham(诺丁汉大学);Max-Planck-Institute for Astrophysics(马克斯·普朗克天体物理研究所)
Voids have emerged as a novel probe of cosmology and large-scale structure. These regions of extreme underdensity are sensitive to physics beyond the standard model of cosmology, and can potentially be used as a testing ground to constrain new physics. We present the first determination of the linear void bias measured in separate universe simulations. Our methods are validated by comparing the separate universe response bias with the clustering bias of voids. We find excellent agreement between the two methods for voids identified in the halo field and the down-sampled dark matter field. For …