Using a void catalog from the SDSS survey, we present the first measurements of void clustering and the corresponding void bias. Over the range 30-200 Mpc/h the void auto-correlation is detected at 5-sigma significance for voids of radius 15-20 Mpc/h. We also measure the void-galaxy cross-correlation at higher signal-to-noise and compare the inferred void bias with the autocorrelation results. Void bias is constant with scale for voids of a given size, but its value falls from 5.6 +/- 1.0 to below zero as the void radius increases from 15 to 30 Mpc/h. The comparison of our measurements with carefully matched galaxy mock catalogs, with no free parameters related to the voids, shows that model predictions can be reliably made for void correlations. We study the dependence of void bias on tracer density and void size with a view to future applications. In combination with our previous lensing measurements of void mass profiles, these clustering measurements provide another step towards using voids as cosmological tracers.
We report the first measurement of the diminutive lensing signal arising from matter underdensities associated with cosmic voids. While undetectable individually, by stacking the weak gravitational shear estimates around 901 voids detected in SDSS DR7 by Sutter et al. (2012a), we find substantial evidence for a depression of the lensing signal compared to the cosmic mean. This depression is most pronounced at the void radius, in agreement with analytical models of void matter profiles. Even with the largest void sample and imaging survey available today, we cannot put useful constraints on the…
We measure weak lensing mass profiles of voids from a volume-limited sample of SDSS Luminous Red Galaxies (LRGs). We find voids using an algorithm designed to maximize the lensing signal by dividing the survey volume into 2D slices, and then finding holes in this 2D distribution of LRGs. We perform a stacked shear measurement on about 20,000 voids with radii between 15-55 Mpc/h and redshifts between 0.16-0.37. We measure the characteristic radial shear signal of voids with a signal-to-noise of 7. The mass profile corresponds to a fractional underdensity of about -0.4 inside the void radius and…
We discuss the universality and self-similarity of void density profiles, for voids in realistic mock luminous red galaxy (LRG) catalogues from the Jubilee simulation, as well as in void catalogues constructed from the SDSS LRG and Main Galaxy samples. Voids are identified using a modified version of the ZOBOV watershed transform algorithm, with additional selection cuts. We find that voids in simulation are self-similar, meaning that their average rescaled profile does not depend on the void size, or -- within the range of the simulated catalogue -- on the redshift. Comparison of the profiles…
Using the redshift-space distortions of void-galaxy cross-correlation function we analyse the dynamics of voids embedded in different environments. We compute the void-galaxy cross-correlation function in the Sloan Digital Sky Survey (SDSS) in terms of distances taken along the line of sight and projected into the sky. We analyse the distortions on the cross-correlation isodensity levels and we find anisotropic isocontours consistent with expansion for large voids with smoothly rising density profiles and collapse for small voids with overdense shells surrounding them. Based on the linear appr…
We present catalogues of voids for the SDSS DR7 redshift survey and for Millennium I simulation mock data. We aim to compare the observations with simulations based on a $Λ$CDM model and a semi-analytic galaxy formation model. We use the void statistics as a test for these models. We assembled a mock catalogue that closely resembles the SDSS DR7 catalogue and carried out a parallel statistical analysis of the observed and simulated catalogue. We find that in the observation and the simulation, voids tend to be equally spherical. The total volume occupied by the voids and their total number are…
We present a cosmic void catalog using the large-scale structure galaxy catalog from the Baryon Oscillation Spectroscopic Survey (BOSS). This galaxy catalog is part of the Sloan Digital Sky Survey (SDSS) Data Release 12 and is the final catalog of SDSS-III. We take into account the survey boundaries, masks, and angular and radial selection functions, and apply the ZOBOV void finding algorithm to the galaxy catalog. We identify a total of 10,643 voids. After making quality cuts to ensure that the voids represent real underdense regions, we obtain 1,228 voids with effective radii spanning the ra…
What do we know about voids in the dark matter distribution given the Sloan Digital Sky Survey (SDSS) and assuming the $Λ\mathrm{CDM}$ model? Recent application of the Bayesian inference algorithm BORG to the SDSS Data Release 7 main galaxy sample has generated detailed Eulerian and Lagrangian representations of the large-scale structure as well as the possibility to accurately quantify corresponding uncertainties. Building upon these results, we present constrained catalogs of voids in the Sloan volume, aiming at a physical representation of dark matter underdensities and at the alleviation o…
Sutter et al. have responded to the criticisms we made of their cosmic void catalogue in our recent paper presenting an alternative catalogue (Nadathur & Hotchkiss 2013). Unfortunately, their response contains several statements which are incorrect, as we point out in this note.
We present a new analysis of the inferred growth rate of cosmic structure measured around voids, using the LOWZ and the CMASS samples in the twelfth data release (DR12) of SDSS. Using a simple multipole analysis we recover a value consistent with $Λ$CDM for the inferred linear growth rate normalized by the linear bias: the $β$ parameter. This is true in both the mock catalogues and the data, where we find $β=0.33\pm0.06$ for the LOWZ sample and $β=0.36\pm0.05$ for the CMASS sample. This work demonstrates that we can expect redshift-space distortions around voids to provide unbiased and accurat…
Recently, Nadathur & Hotchkiss (2013) submitted a paper discussing a new cosmic void catalog. This paper includes claims about the void catalog described in Sutter et al. (2012). In this note, we respond to those claims, clarify some discrepancies between the text of Sutter et al. (2012) and the most recent version of the catalog, and provide some comments on the differences between our catalog and that of Nadathur & Hotchkiss (2013). All updates and documentation for our catalog are available at http://www.cosmicvoids.net.
We report the detection, with a high level of confidence, of coherent outflows around voids found in the seventh data release of the Sloan Digital Sky Survey (SDSS DR7). In particular, we developed a robust <|cos theta|> statistical test to quantify the strength of redshift-space distortions (RSD) associated with extended coherent velocity fields. We consistently find that the vector that joins void centers with galaxies that lie in shells around them is more likely to be perpendicular to the line-of-sight than parallel to it. This effect is clear evidence for the existence of outflows in the …
We perform an Alcock-Paczynski test using stacked cosmic voids identified in the SDSS Data Release 7 main sample and Data Release 10 LOWZ and CMASS samples. We find ~1,500 voids out to redshift $0.6$ using a heavily modified and extended version of the watershed algorithm ZOBOV, which we call VIDE (Void IDentification and Examination). To assess the impact of peculiar velocities we use the mock void catalogs presented in Sutter et al. (2013). We find a constant uniform flattening of 14% along the line of sight when peculiar velocities are included. This flattening appears universal for all voi…
The ellipticity function of cosmic voids exhibits strong dependence on the amplitude of the linear matter power spectrum. Analyzing the most recent void catalogs constructed by Foster and Nelson from the fifth data release of the Sloan Digital Sky Survey, we measure observationally the ellipticity function of giant galaxy voids. Then, we incorporate the redshift distortion and galaxy bias effect into the analytic model of the void ellipticity function and fit it to the observational result by adjusting the value of the power-spectrum normalization with the help of the generalized chi^{2}-minim…
We study the relations between the multimodality of galaxy clusters drawn from the SDSS DR8 and the environment where they reside. We find that multimodal clusters reside in higher density environment than unimodal clusters. We determine morphological types of superclusters and show that clusters in superclusters of spider morphology have higher probabilities to have substructure and larger peculiar velocities of their main galaxies than clusters in superclusters of filament morphology. Our study shows the importance of the role of superclusters as high density environment which affects the pr…
We produce the most comprehensive public void catalog to date using the Sloan Digital Sky Survey Data Release 7 main sample out to redshift z=0.2 and the luminous red galaxy sample out to z=0.44. Using a modified version of the parameter-free void finder ZOBOV, we fully take into account the presence of the survey boundary and masks. Our strategy for finding voids is thus appropriate for any survey configuration. We produce two distinct catalogs: a complete catalog including voids near any masks, which would be appropriate for void galaxy surveys, and a bias-free catalog of voids away from any…
We construct cosmic void catalogues with the DIVE void finder upon SDSS BOSS DR12 and eBOSS DR16 galaxy samples with BAO reconstruction applied, and perform a joint BAO analysis using different types of galaxies and the corresponding voids. The BAO peak is evident for the galaxy-galaxy, galaxy-void, and void-void correlation functions of all datasets, including the ones cross correlating luminous red galaxy and emission line galaxy samples. Two multi-tracer BAO fitting schemes are then tested, one combining the galaxy and void correlation functions with a weight applied to voids, and the other…
The stacked density profile of cosmic voids in the galaxy distribution provides an important tool for the use of voids for precision cosmology. We study the density profiles of voids identified using the ZOBOV watershed transform algorithm in realistic mock luminous red galaxy (LRG) catalogues from the Jubilee simulation, as well as in void catalogues constructed from the SDSS LRG and Main Galaxy samples. We compare different methods for reconstructing density profiles scaled by the void radius and show that the most commonly used method based on counts in shells and simple averaging is statis…
SDSS J0015+0104 is the lowest metallicity low surface brightness dwarf (LSBD) galaxy known. The oxygen abundance in its HII region SDSS J001520.70+010436.9 (at ~1.5 kpc from the galaxy centre) is 12+log(O/H)=7.07 (Guseva et al.). This galaxy, at the distance of 28.4 Mpc, appears to reside deeply in the volume devoid of luminous massive galaxies, known as the Eridanus void. SDSS J235437.29-000501.6 is another Eridanus void LSBD galaxy, with parameter 12+log(O/H)=7.36 (also Guseva et al.). We present the results of their HI observations with the Nancay Radio Telescope revealing their high ratios…
We apply the Alcock-Paczynski (AP) test to the stacked voids identified using the large-scale structure galaxy catalog from the Baryon Oscillation Spectroscopic Survey (BOSS). This galaxy catalog is part of the Sloan Digital Sky Survey (SDSS) Data Release 12 and is the final catalog of SDSS-III. We also use 1000 mock galaxy catalogs that match the geometry, density, and clustering properties of the BOSS sample in order to characterize the statistical uncertainties of our measurements and take into account systematic errors such as redshift space distortions. For both BOSS data and mock catalog…
We present and study cosmic voids identified using the watershed void finder VIDE in the Sloan Digital Sky Survey Data Release 9, compare these voids to ones identified in mock catalogs, and assess the impact of the survey mask on void statistics such as number functions, ellipticity distributions, and radial density profiles. The nearly 1,000 identified voids span three nearly volume-limited samples from redshift z = 0.43 to 0.7. For comparison we use 98 of the publicly available 2LPT-based mock galaxy catalogs of Manera et al., and also generate our own mock catalogs by applying a Halo Occup…
We present a void clustering analysis in configuration-space using the completed Sloan Digital Sky Survey IV (SDSS-IV) extended Baryon Oscillation Spectroscopic Survey (eBOSS) DR16 samples. These samples consist of Luminous Red Galaxies (LRG) combined with the high redshift tail of the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) DR12 CMASS galaxies (called as LRG+CMASS sample), Emission Line Galaxies (ELG) and quasars (QSO). We build void catalogues from the three eBOSS DR16 samples using a ZOBOV-based algorithm, providing 2,814 voids, 1,801 voids and 4,347 voids in the LRG+CMASS, …
We investigate the ability of three reconstruction techniques to analyze and investigate weblike features and geometries in a discrete distribution of objects. The three methods are the linear Delaunay Tessellation Field Estimator (DTFE), its higher order equivalent Natural Neighbour Field Estimator (NNFE) and a version of Kriging interpolation adapted to the specific circumstances encountered in galaxy redshift surveys, the Natural Lognormal Kriging technique. DTFE and NNFE are based on the local geometry defined by the Voronoi and Delaunay tessellations of the galaxy distribution. The three …
The study of the interesting cosmological properties of voids in the Universe depends on the efficient and robust identification of such voids in galaxy redshift surveys. Recently, Sutter et al. (2012) have published a public catalogue of voids in the Sloan Digital Sky Survey Data Release 7 main galaxy and luminous red galaxy samples, using the void-finding algorithm ZOBOV, which is based on the watershed transform. We examine the properties of this catalogue and show that it suffers from several problems and inconsistencies, including the identification of some extremely overdense regions as …
We analyse the clustering of cosmic voids using a numerical simulation and the main galaxy sample from the Sloan Digital Sky Survey. We take into account the classification of voids into two types that resemble different evolutionary modes: those with a rising integrated density profile (void-in-void mode, or R-type) and voids with shells (void-in-cloud mode, or S-type). The results show that voids of the same type have stronger clustering than the full sample. We use the correlation analysis to define void clumps, associations with at least two voids separated by a distance of at most the mea…
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）
We perform a statistical study focused on void environments. We examine galaxy density profiles around voids in the SDSS, finding a correlation between void--centric distance to the shell of maximum density and void radius when a maximum in overdensity exists. We analyze voids with and without a surrounding over-dense shell in the SDSS. We find that small voids are more frequently surrounded by over-dense shells whereas the radial galaxy density profile of large voids tends to rise smoothly towards the mean galaxy density. We analyse the fraction of voids surrounded by overdense shells finding…
We study the clustering of voids using $N$-body simulations and simple theoretical models. The excursion-set formalism describes fairly well the abundance of voids identified with the watershed algorithm, although the void formation threshold required is quite different from the spherical collapse value. The void cross bias $b_{\rm c} $ is measured and its large-scale value is found to be consistent with the peak background split results. A simple fitting formula for $b_{\rm c} $ is found. We model the void auto-power spectrum taking into account the void biasing and exclusion effect. A good f…
Robustness of cosmic void statistics: insights from SDSS DR7 and the ELUCID simulation
Shanghai Astronomical Observatory（上海天文台）；State Key Laboratory of Dark Matter Physics, Tsung-Dao Lee Institute & School of Physics and Astronomy, Shanghai Jiao Tong University（暗物质物理全国重点实验室、李政道理论与计算科学中心、物理与天文学院，上海交通大学）；Shanghai Key Laboratory for Particle Physics and Cosmology, and Key Laboratory for Particle Physics, Astrophysics and Cosmology Ministry of Education, Shanghai Jiao Tong University（粒子物理与宇宙学上海市重点实验室、教育部粒子物理、天体物理与宇宙学重点实验室，上海交通大学）；School of Aerospace Science and Technology, Xidian University（空间科学与技术学院，西安电子科技大学）
The shapes of cosmic voids are prone to distortions by the external tidal forces since their low-densities imply a lower internal resistance. This susceptibility of the void shapes to the tidal distortions makes them useful as an indicator of the large-scale tidal and density fields, despite the practical difficulty in defining them. Using the void catalog constructed by Pan et al. (2012) from the Seventh Data Release of the Sloan Digital Sky Survey (SDSS DR7), we detect a clear 4 sigma signal of spatial correlations of the void shapes on the scale of 20 Mpc/h and show that the signal is robus…
We investigate the necessary methodology to optimally measure the baryon acoustic oscillation (BAO) signal, from voids based on galaxy redshift catalogues. To this end, we study the dependency of the BAO signal on the population of voids classified by their sizes. We find for the first time the characteristic features of the correlation function of voids including the first robust detection of BAOs in mock galaxy catalogues. These show an anti-correlation around the scale corresponding to the smallest size of voids in the sample (the void exclusion effect), and dips at both sides of the BAO pe…
We present an analysis of the anisotropic redshift-space void-galaxy correlation in configuration space using the Sloan Digital Sky Survey extended Baryon Oscillation Spectroscopic Survey (eBOSS) Data Release 16 luminous red galaxy (LRG) sample. This sample consists of LRGs between redshifts 0.6 and 1.0, combined with the high redshift $z>0.6$ tail of the Baryon Oscillation Spectroscopic Survey Data Release 12 CMASS sample. We use a reconstruction method to undo redshift-space distortion (RSD) effects from the galaxy field before applying a watershed void-finding algorithm to remove bias from …
We study the relations between the multimodality of galaxy clusters drawn from the SDSS DR8 and the environment where they reside. As cluster environment we consider the global luminosity density field, supercluster membership, and supercluster morphology. We use 3D normal mixture modelling, the Dressler-Shectman test, and the peculiar velocity of cluster main galaxies as signatures of multimodality of clusters. We calculate the luminosity density field to study the environmental densities around clusters, and to find superclusters where clusters reside. We determine the morphology of superclu…
Multi-tracer mass bias in matched cosmic voids from SDSS DR7 and the ELUCID constrained simulation
Shanghai Astronomical Observatory（上海天文台）；Tsung-Dao Lee Institute & School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院、汤忠道研究院）；Shanghai Key Laboratory for Particle Physics and Cosmology, and Key Laboratory for Particle Physics, Astrophysics and Cosmology Ministry of Education, Shanghai Jiao Tong University（上海交通大学粒子物理与宇宙学上海市重点实验室、粒子物理、天体物理与宇宙学教育部重点实验室）
We study scaling behaviour of statistics of voids in the context of the halo model of nonlinear large-scale structure. The halo model allows us to understand why the observed galaxy void probability obeys hierarchical scaling, even though the premise from which the scaling is derived is not satisfied. We argue that the commonly observed negative binomial scaling is not fundamental, but merely the result of the specific values of bias and number density for typical galaxies. The model implies quantitative relations between void statistics measured for two populations of galaxies, such as SDSS r…
We study the distribution of cosmic voids and void galaxies using Sloan Digital Sky Survey Data Release 7 (SDSS DR7). Using the VoidFinder algorithm as described by Hoyle 2002, we identify 1054 statistically significant voids in the northern galactic hemisphere with radii > 10 h^{-1} Mpc. The filling factor of voids in the sample volume is 62%. The largest void is just over 30 h^{-1} Mpc in effective radius. The median effective radius is 17 h^{-1} Mpc. The voids are found to be significantly underdense, with density contrast δ< -0.85 at the edges of the voids. The radial density profiles of t…
Cosmic voids defined as a subset of Delaunay Triangulation (DT) circumspheres have been used to measure the Baryon Acoustic Oscillations (BAO) scale; providing tighter constraints on cosmological parameters when combined with matter tracers. These voids are defined as spheres larger than a given radius threshold, which is constant over the survey volume. However, the response of these void tracers to observational systematics has not yet been studied. In this work we analyse the response of void clustering to selection effects. We find for the case of moderate (<20 per cent) incompleteness, vo…
Do void statistics contain information beyond the tracer 2-point correlation function? Yes! As we vary the sum of the neutrino masses, we find void statistics contain information absent when using just tracer 2-point statistics. Massive neutrinos uniquely affect cosmic voids. We explore their impact on void clustering using both the DEMNUni and MassiveNuS simulations. For voids, neutrino effects depend on the observed void tracers. As the neutrino mass increases, the number of small voids traced by cold dark matter particles increases and the number of large voids decreases. Surprisingly, when…
Giant Metrewave Radio Telescope (GMRT) HI observations, done as part of an ongoing study of dwarf galaxies in the Lynx-Cancer void, resulted in the discovery of a triplet of extremely gas rich galaxies located near the centre of the void.The triplet members SDSS J0723+3621, J0723+3622 and J0723+3624 have absolute magnitudes M_B of -14.2, -11.9 and -9.7 and M(HI)/L_B of \sim 2.9, ~10 and ~25, respectively. The gas mass fractions, as derived from the SDSS photometry and the GMRT data are 0.93, 0.997, 0.997 respectively. The faintest member of this triplet SDSS J0723+3624 is one of the most gas r…
The Baryon Acoustic Oscillations (BAO) refer to the ripples of material density in the Universe. As the most direct density tracers in the universe, galaxies have been commonly used in studies of BAO peak detection. The spatial number density of galaxies, to a certain extent, reflects the distribution of the material density of our Universe. Using galaxies as matter tracers, we can construct more overlapping empty spheres (DT voids) than the matter tracers, via Delaunay Triangulation technique. We show that their radii excellently reflect the galaxy number density round them, and they can serv…
(Abridged) We present the results of the complex study of the low surface brightness dwarf (LSBD) gas-rich galaxies J0723+3621, J0737+4724 and J0852+1350, which reside in the nearby Lynx-Cancer void. Their ratios M(HI)/L_B, according to HI data obtained with the NRT, are respectively ~3.9, ~2, ~2.6. For the two latter galaxies, we derived oxygen abundance corresponding to the value of 12+log(O/H) <~7.3, using spectra from the Russian 6m telescope and from the SDSS database. We found two additional blue LSB dwarfs, J0723+3622 and J0852+1351, which appear to be physical companions of J0723+3621 …
Taking N-body simulations with volumes and particle densities tuned to match the SDSS DR7 spectroscopic main sample, we assess the ability of current void catalogs (e.g., Sutter et al. 2012b) to distinguish a model of coupled dark matter-dark energy from ΛCDM cosmology using properties of cosmic voids. Identifying voids with the VIDE toolkit, we find no statistically significant differences in the ellipticities, but find that coupling produces a population of significantly larger voids, possibly explaining the recent result of Tavasoli et al. (2013). In addition, we use the universal density p…
We present a detailed description of our void finding algorithm which is an extension of the prescription by Hoyle and Vogeley (2002). We include a discussion of the reproducibility and robustness of the algorithm as well as the statistical significance of the detected voids. We apply our void finder to the Data Release 5 (DR5) of the Sloan Digital Sky Survey (SDSS) and identify 232 cosmological voids. A void catalog which contains the most salient properties of the detected voids is created. We present a statistical analysis of the distribution of the size, shape and orientation of our identi…
We investigate the impact of filament and void environments on galaxies, looking for residual effects beyond the known relations with environment density. We quantified the host environment of galaxies as the distance to the spine of the nearest filament, and compared various galaxy properties within 12 bins of this distance. We considered galaxies up to 10 $h^{-1}$Mpc from filaments, i.e. deep inside voids. The filaments were defined by a point process (the Bisous model) from the Sloan Digital Sky Survey data release 10. In order to remove the dependence of galaxy properties on the environmen…
The Lyman-alpha forest is a unique probe of large-scale matter density fluctuations at high redshift (z > 2). It is possible to obtain 3D maps of the matter distribution from Lyman-alpha data, using tomographic reconstruction methods. Here, we present the largest tomographic map of matter fluctuations at z > 2, over the Gpc^3 volume covered by Lyman-alpha forest from SDSS-IV quasar spectra in the Stripe 82 field. We present a catalog of high-redshift voids constructed from this map. The measurement of the cross-correlation between these voids and the Lyman-alpha forest provides the first obser…
Recent works have shown that the properties of galaxy populations in dark matter halos vary with large-scale environments. These results suggest a variation in the halo occupation distribution (HOD) in extreme density environments. To analyse these effects, we identify cosmic voids and future virialised structures (FVS) in the SDSS-DR12 and estimate the HOD within these superstructures using group catalogues as dark matter halo proxies. Our goal is to use observational galaxy data to characterise the HOD within voids and FVS, explore the different properties of these galaxies populations and c…
We measure the projected spatial correlation function w_p(r_p) from a large sample combining GALEX ultraviolet imaging with the SDSS spectroscopic sample. We study the dependence of the clustering strength for samples selected on (NUV - r)_abs color, specific star formation rate (SSFR), and stellar mass. We find that there is a smooth transition in the clustering of galaxies as a function of this color from weak clustering among blue galaxies to stronger clustering for red galaxies. The clustering of galaxies within the "green valley" has an intermediate strength, and is consistent with that e…
In measurements of the clustering dipole from all-sky surveys, an important problem is the lack of information about galaxy distribution in the so-called Zone of Avoidance (ZoA). The existence of the Local Void (LV) has a systematic effect on these measurements. If the ZoA is randomly filled with mock galaxies, then the calculated acceleration of the Local Group of galaxies (LG) has a spurious component, resulting from the lack of real galaxies in the intersection of the LV with the ZoA. This component affects both the misalignment angle between the clustering dipole and the CMB dipole, and th…
Cosmic voids offer an extraordinary opportunity to study the effects of massive neutrinos on cosmological scales. Because they are freely streaming, neutrinos can penetrate the interior of voids more easily than cold dark matter or baryons, which makes their relative contribution to the mass budget in voids much higher than elsewhere in the Universe. In simulations it has recently been shown how various characteristics of voids in the matter distribution are affected by neutrinos, such as their abundance, density profiles, dynamics, and clustering properties. However, the tracers used to ident…
The Euclid space telescope will survey a large dataset of cosmic voids traced by dense samples of galaxies. In this work we estimate its expected performance when exploiting angular photometric void clustering, galaxy weak lensing and their cross-correlation. To this aim, we implement a Fisher matrix approach tailored for voids from the Euclid photometric dataset and present the first forecasts on cosmological parameters that include the void-lensing correlation. We examine two different probe settings, pessimistic and optimistic, both for void clustering and galaxy lensing. We carry out forec…
The large-scale structure of the universe can only be observed via luminous tracers of the dark matter. However, the clustering statistics of tracers are biased and depend on various properties, such as their host-halo mass and assembly history. On very large scales this tracer bias results in a constant offset in the clustering amplitude, known as linear bias. Towards smaller nonlinear scales, this is no longer the case and tracer bias becomes a complicated function of scale and time. We focus on tracer bias centred on cosmic voids, depressions of the density field that spatially dominate the…
