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We present photometric redshifts (photo- z) for the deep wide fields of the Physics of the Accelerating Universe Survey (PAUS), covering an area of |$\sim$| 50 deg |$^{2}$|⁠ , for |$\sim$| 1.8 million objects up to |$i_{\rm {AB}}\lt 23$|⁠. The PAUS deep wide fields overlap with the W1 and W3 fields from CFHTLenS and the G09 field from KiDS/GAMA. Photo- z are estimated using the 40 narrow bands (NB) of PAUS and the broad-bands (BB) of CFHTLenS and KiDS. We compute the redshifts with the SED template-fitting code bcnz , with a modification in the calibration technique of the zero-point between the observed and the modelled fluxes, that removes any dependence on spectroscopic redshift samples. We enhance the redshift accuracy by introducing an additional photo- z estimate (⁠|$z_{\textrm {b}}$|⁠), obtained through the combination of the bcnz and the BB-only photo- z. Comparing with spectroscopic redshift estimates (⁠|$z_{\textrm {s}}$|⁠), we obtain a |$\sigma _{68} \simeq 0.020$| for all galaxies with |$i_{\rm {AB}}\lt 23$| and a typical bias |$|z_{\textrm {b}}\!-\!z_{\textrm {s}}|$| smaller than 0.01. For |$z_{\textrm {b}} \sim (0.10\!-\!0.75)$|⁠ , we find |$\sigma _{68} \simeq (0.003\!-\!0.02)$|⁠ , this is a factor of |$10\!-\!2$| higher accuracy than the corresponding BB-only results. We obtain similar performance when we split the samples into red (passive) and blue (active) galaxies. We validate the redshift probability |$p(z)$| obtained by bcnz and compare its performance with that of |$z_{\textrm {b}}$|⁠. These photo- z catalogues will facilitate important science cases, such as the study of galaxy clustering and intrinsic alignment at high redshifts (⁠|$z \lesssim 1$|⁠) and faint magnitudes. [ABSTRACT FROM AUTHOR]

Extracting precise cosmology from weak lensing surveys requires modelling the non-linear matter power spectrum, which is suppressed at small scales due to baryonic feedback processes. However, hydrodynamical galaxy formation simulations make widely varying predictions for the amplitude and extent of this effect. We use measurements of Dark Energy Survey Year 3 weak lensing (WL) and Atacama Cosmology Telescope DR5 kinematic Sunyaev–Zel'dovich (kSZ) to jointly constrain cosmological and astrophysical baryonic feedback parameters using a flexible analytical model, 'baryonification'. First, using WL only, we compare the |$S_8$| constraints using baryonification to a simulation-calibrated halo model, a simulation-based emulator model, and the approach of discarding WL measurements on small angular scales. We find that model flexibility can shift the value of |$S_8$| and degrade the uncertainty. The kSZ provides additional constraints on the astrophysical parameters, with the joint WL + kSZ analysis constraining |$S_8=0.823^{+0.019}_{-0.020}$|⁠. We measure the suppression of the non-linear matter power spectrum using WL + kSZ and constrain a mean feedback scenario that is more extreme than the predictions from most hydrodynamical simulations. We constrain the baryon fractions and the gas mass fractions and find them to be generally lower than inferred from X-ray observations and simulation predictions. We conclude that the WL + kSZ measurements provide a new and complementary benchmark for building a coherent picture of the impact of gas around galaxies across observations. [ABSTRACT FROM AUTHOR]

Recent quasar absorption line observations suggest that reionization may end as late as |$z \approx 5.3$|⁠. As a means to search for large neutral hydrogen islands at |$z\ \lt\ 6$|⁠ , we revisit long dark gaps in the Ly  |$\beta$| forest in Very Large Telescope/X-Shooter and Keck/Echellette Spectrograph and Imager quasar spectra. We stack the Ly  |$\alpha$| forest corresponding to both edges of these Ly  |$\beta$| dark gaps and identify a damping wing-like extended absorption profile. The average redshift of the stacked forest is |$z=5.8$|⁠. By comparing these observations with reionization simulations, we infer that such a damping wing-like feature can be naturally explained if these gaps are at least partially created by neutral islands. Conversely, simulated dark gaps lacking neutral hydrogen struggle to replicate the observed damping wing features. Furthermore, this damping wing-like profile implies that the volume-averaged neutral hydrogen fraction must be |$\langle x_{\rm H\,{\small {I}}} \rangle \ge 6.1 \pm 3.9~{{\ \rm per\ cent}}$| at |$z = 5.8$|⁠. Our results offer robust evidence that reionization extends below |$z=6$|⁠. [ABSTRACT FROM AUTHOR]

In the context of the cosmological and constrained Exploring the Local Universe with the reConstructed Initial Density field (ELUCID) simulation, this study explores the statistical characteristics of filaments within the cosmic web, focussing on aspects such as the distribution of filament lengths and their radial density profiles. Using the classification of the cosmic web environment through the Hessian matrix of the density field, our primary focus is on how cosmic structures react to the two variables |$R_{\rm s}$| and |$\lambda _{\rm th}$|⁠. The findings show that the volume fractions of knots, filaments, sheets, and voids are highly influenced by the threshold parameter |$\lambda _{\rm th}$|⁠ , with only a slight influence from the smoothing length |$R_{\rm s}$|⁠. The central axis of the cylindrical filament is pinpointed using the medial-axis thinning algorithm of the COsmic Web Skeleton (COWS) method. It is observed that median filament lengths tend to increase as the smoothing lengths increase. Analysis of filament length functions at different values of |$R_{\rm s}$| indicates a reduction in shorter filaments and an increase in longer filaments as |$R_{\rm s}$| increases, peaking around |$2.5R_{\rm s}$|⁠. The study also shows that the radial density profiles of filaments are markedly affected by the parameters |$R_{\rm s}$| and |$\lambda _{\rm th}$|⁠ , showing a valley at approximately |$2R_{\rm s}$|⁠ , with increases in the threshold leading to higher amplitudes of the density profile. Moreover, shorter filaments tend to have denser profiles than their longer counterparts. [ABSTRACT FROM AUTHOR]

Patchy reionization generates kinematic Sunyaev–Zel'dovich (kSZ) anisotropies in the cosmic microwave background (CMB). Large-scale velocity perturbations along the line of sight modulate the small-scale kSZ power spectrum, leading to a trispectrum (or four-point function) in the CMB that depends on the physics of reionization. We investigate the challenges in detecting this trispectrum and use tools developed for CMB lensing, such as realization-dependent bias subtraction and cross-correlation based estimators, to counter uncertainties in the instrumental noise and assumed CMB power spectrum. We also find that both lensing and extragalactic foregrounds can impart larger trispectrum contributions than the reionization kSZ signal. We present a range of mitigation methods for both of these sources of contamination, validated on microwave-sky simulations. We use ACT DR6 and Planck data to calculate an upper limit on the reionization kSZ trispectrum from a measurement dominated by foregrounds. The upper limit is about 50 times the signal predicted from recent simulations. [ABSTRACT FROM AUTHOR]

We present constraints on the dark scattering model through cosmic shear measurements from the Kilo Degree Survey (KiDS-1000), using an accelerated pipeline with novel emulators produced with CosmoPower. Our main emulator, for the dark scattering non-linear matter power spectrum, is trained on predictions from the halo model reaction framework, previously validated against simulations. Additionally, we include the effects of baryonic feedback from HMCode2016 , whose contribution is also emulated. We analyse the complete set of statistics of KiDS-1000, namely band powers, COSEBIs, and correlation functions, for dark scattering in two distinct cases. In the first case, taking into account only KiDS cosmic shear data, we constrain the amplitude of the dark energy–dark matter interaction to be |$\vert A_{\rm ds} \vert \lesssim 20$| |$\rm b\,GeV^{-1}$| at 68  per cent C.L. Furthermore, we add information from the cosmic microwave background (CMB) from Planck, along with baryon acoustic oscillations (BAO) from 6dFGS, SDSS, and BOSS, approximating a combined weak lensing+CMB+BAO analysis. From this combination, we constrain |$A_{\rm ds} = 10.6^{+4.5}_{-7.3}$| |$\rm b\,GeV^{-1}$| at 68  per cent C.L. We confirm that with this estimated value of |$A_{\rm ds}$| the interacting model considered in this work offers a promising alternative to solve the |$S_8$| tension. [ABSTRACT FROM AUTHOR]

The detailed nature of dark energy remains a mystery, leaving the possibility that its effects might be explained by changes to the laws of gravity on large scales. The peculiar velocities of galaxies directly trace the strength of gravity on cosmic scales and provide a means to further constrain such models. We generate constraints on different scenarios of gravitational physics by measuring peculiar velocity (PV) and galaxy clustering two-point correlations, using redshifts and distances from the 6-degree Field Galaxy Survey and the Sloan Digital Sky Survey PV samples, and fitting them against models characteristic of different cosmologies. Our best-fitting results are all found to be in statistical agreement with general relativity, in which context we measure the low-redshift growth of structure to be |$f\sigma _8 = 0.329^{+0.081}_{-0.083}$|⁠ , consistent with the prediction of the standard Lambda cold dark matter model. We also fit the modified gravity scenarios of Dvali–Gabadadze–Porrati and a Hu–Sawicki model of |$f(R)$| gravity, finding the |$2\sigma$| limit of their characteristic parameters to be |$r_{\rm c}H_0/c\gt 6.987$| and |$-\log _{10}(|f_{R0}|)\gt 4.703$|⁠ , respectively. These constraints are comparable to other literature values, though it should be noted that they are significantly affected by the prior adopted for their characteristic parameters. When applied to much larger upcoming PV surveys such as DESI, this method will place rapidly improving constraints on modified gravity models of cosmic expansion and growth. [ABSTRACT FROM AUTHOR]

Deep learning (DL) has recently been proposed as a novel approach for 21cm foreground removal. Before applying DL to real observations, it is essential to assess its consistency with established methods, its performance across various simulation models, and its robustness against instrumental systematics. This study develops a commonly used U-Net and evaluates its performance for post-reionization foreground removal across three distinct sky simulation models based on pure Gaussian realizations, the Lagrangian perturbation theory, and the Planck sky model. Consistent outcomes across the models are achieved provided that training and testing data align with the same model. On average, the residual foreground in the U-Net reconstructed data is |$\sim 10~{{\ \rm per\ cent}}$| of the signal across angular scales at the considered redshift range. Comparable results are found with traditional approaches. However, blindly using a network trained on one model for data from another model yields inaccurate reconstructions, emphasizing the need for consistent training data. The study then introduces frequency-dependent Gaussian beams and bandpass fluctuations to the test data. The network struggles to denoise data affected by 'unexpected' systematics without prior information. However, after re-training consistently with systematics-contaminated data, the network effectively restores its reconstruction accuracy. Our results highlight the importance of incorporating prior knowledge during network training compared with established blind methods. Our work provides critical guidelines for using DL for 21cm foreground removal, tailored to specific data attributes. Notably, it is the first time that DL has been applied to the Planck sky model being most realistic foregrounds at present. [ABSTRACT FROM AUTHOR]

This study investigates the clustering and bias of Luminous Red Galaxies (LRG) in the BOSS-LOWZ, -CMASS, -COMB, and eBOSS samples, using two types of simulated lightcones: (i) high-fidelity lightcones from Uchuu N -body simulation, employing SHAM technique to assign LRG to (sub)haloes, and (ii) 16 000 covariance lightcones from GLAM-Uchuu N -body simulations, including LRG using HOD data from Uchuu. Our results indicate that Uchuu and glam lightcones closely replicate BOSS/eBOSS data, reproducing correlation function and power spectrum across scales from redshifts 0.2 to 1.0, from 2 to |$150 \,h^{-1}\,\mathrm{Mpc}$| in configuration space, from 0.005 to |$0.7\, h\,\mathrm{Mpc}^{-1}$| in Fourier space, and across different LRG stellar masses. Furthermore, comparing with existing MD-Patchy and EZmock BOSS/eBOSS lightcones based on approximate methods, our GLAM-Uchuu lightcones provide more precise clustering estimates. We identify significant deviations from observations within |$20 \,h^{-1}\,\mathrm{Mpc}$| scales in MD-Patchy and EZmock , with our covariance matrices indicating that these methods underestimate errors by between 10 per cent and 60 per cent. Lastly, we explore the impact of cosmology on galaxy clustering. Our findings suggest that, given the current level of uncertainties in BOSS/eBOSS data, distinguishing models with and without massive neutrino effects on large-scale structure (LSS) is challenging. This paper highlights the Uchuu and GLAM-Uchuu simulations' robustness in verifying the accuracy of Planck cosmological parameters, providing a strong foundation for enhancing lightcone construction in future LSS surveys. We also demonstrate that generating thousands of galaxy lightcones is feasible using N -body simulations with adequate mass and force resolution. [ABSTRACT FROM AUTHOR]

Combining different observational probes, such as galaxy clustering and weak lensing, is a promising technique for unveiling the physics of the Universe with upcoming dark energy experiments. The galaxy redshift sample from the Dark Energy Spectroscopic Instrument (DESI) will have a significant overlap with major ongoing imaging surveys specifically designed for weak lensing measurements: The Kilo-Degree Survey (KiDS), the Dark Energy Survey (DES), and the Hyper Suprime-Cam (HSC) survey. In this work, we analyse simulated redshift and lensing catalogues to establish a new strategy for combining high-quality cosmological imaging and spectroscopic data, in view of the first-year data assembly analysis of DESI. In a test case fitting for a reduced parameter set, we employ an optimal data compression scheme able to identify those aspects of the data that are most sensitive to cosmological information and amplify them with respect to other aspects of the data. We find this optimal compression approach is able to preserve all the information related to the growth of structures.

Context. Weak gravitational lensing offers a powerful method to investigate the projected matter density distribution within galaxy clusters, granting crucial insights into the broader landscape of dark matter on cluster scales. Aims. In this study, we make use of the large photometric galaxy cluster data set derived from the publicly available Third Data Release of the Kilo-Degree Survey, along with the associated shear signal. Our primary objective is to model the peculiar sharp transition in the cluster profile slope, that is what is commonly referred to as the splashback radius. The data set under scrutiny includes 6962 galaxy clusters, selected by AMICO (an optimised detection algorithm of galaxy clusters) on the KiDS-DR3 data, in the redshift range of 0.1 ≤ z ≤ 0.6, all observed at a signal-to-noise ratio greater than 3.5. Methods. Employing a comprehensive Bayesian analysis, we model the stacked excess surface mass density distribution of the clusters. We adopt a model from recent results on numerical simulations that capture the dynamics of both orbiting and infalling materials, separated by the region where the density profile slope undergoes a pronounced deepening. Results. We find that the adopted profile successfully characterizes the cluster masses, consistent with previous works, and models the deepening of the slope of the density profiles measured with weak-lensing data up to the outskirts. Moreover, we measure the splashback radius of galaxy clusters and show that its value is close to the radius within which the enclosed overdensity is 200 times the mean matter density of the Universe, while theoretical models predict a larger value consistent with a low accretion rate. This points to a potential bias of optically selected clusters preferentially characterized by a high density at small scales compared to a pure mass-selected cluster sample. [ABSTRACT FROM AUTHOR]

Although it is well known that the bulk of dark matter (DM) has to be cold, the existence of an additional sub-dominant, hot species remains a valid possibility. In this paper we investigate the potential of the cosmic shear power spectrum to constrain such a mixed (hot plus cold) DM scenario with two additional free parameters, the hot-to-total DM fraction (fhdm) and the thermal mass of the hot component (mhdm). Running a Bayesian inference analysis for both the Kilo-Degree Survey cosmic shear data (KiDS-1000) as well as the cosmic microwave background (CMB) temperature and polarisation data from Planck, we derive new constraints for the mixed DM scenario. We find a 95% confidence limit of fhdm < 0.08 for a very hot species of mhdm ≤ 20 eV. This constraint is weakened to fhdm < 0.25 for mhdm ≤ 80 eV. Scenarios with masses above mhdm ∼ 200 eV remain unconstrained by the data. Next to providing limits, we investigate the potential of mixed DM to address the clustering (or S8) tension between lensing and the CMB. We find a reduction of the 2D (Ωm − S8) tension from 2.9σ to 1.6σ when going from a pure cold DM to a mixed DM scenario. When computing the 1D Gaussian tension on S8 the improvement is milder, from 2.4σ to 2.0σ. [ABSTRACT FROM AUTHOR]

Galaxy clustering measurements are a key probe of the matter density field in the Universe. With the era of precision cosmology upon us, surveys rely on precise measurements of the clustering signal for meaningful cosmological analysis. However, the presence of systematic contaminants can bias the observed galaxy number density, and thereby bias the galaxy two-point statistics. As the statistical uncertainties get smaller, correcting for these systematic contaminants becomes increasingly important for unbiased cosmological analysis. We present and validate a new method for understanding and mitigating both additive and multiplicative systematics in galaxy clustering measurements (two-point function) by joint inference of contaminants in the galaxy overdensity field (one-point function) using a maximum-likelihood estimator (MLE). We test this methodology with Kilo-Degree Survey-like mock galaxy catalogues and synthetic systematic template maps. We estimate the cosmological impact of such mitigation by quantifying uncertainties and possible biases in the inferred relationship between the observed and the true galaxy clustering signal. Our method robustly corrects the clustering signal to the sub-per cent level and reduces numerous additive and multiplicative systematics from |$1.5 \sigma$| to less than |$0.1\sigma$| for the scenarios we tested. In addition, we provide an empirical approach to identifying the functional form (additive, multiplicative, or other) by which specific systematics contaminate the galaxy number density. Even though this approach is tested and geared towards systematics contaminating the galaxy number density, the methods can be extended to systematics mitigation for other two-point correlation measurements. [ABSTRACT FROM AUTHOR]

We examine the sky distribution of radio galaxies in the NRAO VLA Sky Survey (NVSS) and the Rapid ASKAP Continuum Survey (RACS). Analyses of these samples have reported tension between their inferred dipoles and the kinematic dipole of the cosmic microwave background (CMB). This represents a challenge to the traditional assumption that the Universe is homogeneous and isotropic on large scales: the cosmological principle. We find that NVSS and RACS contain local radio sources that give a non-negligible contribution to the overall dipole signal. These need to be adequately accounted for since the aim is to probe the composition of the Universe at large scales. By appropriately considering these sources, the inferred dipole amplitude in either sample is reduced. None the less, we find support for a dipole aligning with that of the CMB but larger in amplitude, especially in the joint analysis. However, the 'clustering dipole' – the contribution of local sources to the net inferred dipole – appears to align with the direction of the CMB dipole, and its magnitude increases as deeper nearby sources are considered up to a comoving distance of ≈130 Mpc (h  = 0.7). The significance of this observation in the context of the cosmological principle is unclear and prompts further inquiry. [ABSTRACT FROM AUTHOR]

The spectroscopic survey of the China's Space Survey Telescope (CSST) is expected to obtain a huge number of slitless spectra, including more than one hundred million galaxy spectra and millions of active galactic nuclei (AGNs) spectra. By making use of these spectra, we can measure the Baryon Acoustic Oscillation (BAO) signals over large redshift ranges with excellent precisions. In this work, we predict the CSST measurements of the post-reconstruction galaxy power spectra at |$0\lt z\lt 1.2$| and pre-reconstruction AGN power spectra at |$0\lt z\lt 4$|⁠ , and derive the BAO signals at different redshift bins by constraining the BAO scaling parameters using the Markov Chain Monte Carlo method. Our result shows that the CSST spectroscopic survey can provide accurate BAO measurements with precisions higher than 1 and 3 per cent for the galaxy and AGN surveys, respectively. By comparing with current measurements in the same range at low redshifts, this can improve the precisions by a factor of |$2\sim 3$|⁠ , and similar precisions can be obtained in the pessimistic case. We also investigate the constraints on the cosmological parameters using the measured BAO data by the CSST , and obtain stringent constraint results for the energy density of dark matter, Hubble constant, and equation of state of dark energy. [ABSTRACT FROM AUTHOR]

This work explores the relationships between galaxy sizes and related observable galaxy properties in a large volume cosmological hydrodynamical simulation. The objectives of this work are to develop a better understanding of both the correlations between galaxy properties and the influence of environment on galaxy physics in order to build an improved model for the galaxy sizes, building off of the fundamental plane. With an accurate intrinsic galaxy size predictor, the residuals in the observed galaxy sizes can potentially be used for multiple cosmological applications, including making measurements of galaxy velocities in spectroscopic samples, estimating the rate of cosmic expansion, and constraining the uncertainties in the photometric redshifts of galaxies. Using projection pursuit regression, the model accurately predicts intrinsic galaxy sizes and have residuals which have limited correlation with galaxy properties. The model decreases the spatial correlation of galaxy size residuals by a factor of ∼5 at small scales compared to the baseline correlation when the mean size is used as a predictor. [ABSTRACT FROM AUTHOR]

It has long been known that galaxy shapes align coherently with the large-scale density field. Characterizing this effect is essential to interpreting measurements of weak gravitational lensing, the deflection of light from distant galaxies by matter overdensities along the line of sight, as it also produces coherent galaxy alignments that we wish to interpret in terms of a cosmological model. Existing direct measurements of intrinsic alignments using galaxy samples with high-quality shape and redshift measurements typically use well-understood but sub-optimal projected estimators, which do not make good use of the information in the data when comparing those estimators to theoretical models. We demonstrate a more optimal estimator, based on a multipole expansion of the correlation functions or power spectra, for direct measurements of galaxy intrinsic alignments. We show that even using the lowest order multipole alone increases the significance of inferred model parameters using simulated and real data, without any additional modelling complexity. We apply this estimator to measurements of parameters of the non-linear alignment model using data from the Sloan Digital Sky survey, demonstrating consistent results with a factor of ∼2 greater precision in parameter fits to intrinsic alignments models. This result is functionally equivalent to quadrupling the survey area, but without the attendant costs – thereby demonstrating the value in using this new estimator in current and future intrinsic alignments measurements using spectroscopic galaxy samples. [ABSTRACT FROM AUTHOR]

Context. This Letter explores the potential role of primordial black holes (PBHs) to address cosmological tensions as the presence of more massive than expected galaxies at high redshifts, as indicated by recent James Webb Space Telescope observations. Aims. Motivated by inflation models that enhance the power at scales beyond the observable range that produce PBHs with Schechter-like mass functions, we aim to explain the excess of high redshift galaxies via a modification of the Λ cold dark matter power spectrum that consists in adding (i) a blue spectral index nb at kpiv = 10/Mpc and (ii) Poisson and isocurvature contributions from massive PBHs that only make up 0.5% of the dark matter. Methods. We simulated these models using the SWIFT code and find an increased abundance of high redshift galaxies in simulations that include PBHs. We compared these models to estimates from James Webb Space Telescope observations. Results. Unlike the Λ cold dark matter model, the inclusion of PBHs allowed us to reproduce the observations with reasonable values for the star formation efficiency. Furthermore, the power spectra we adopted potentially produce PBHs that can serve as seeds for supermassive black holes with masses 7.57 × 104 M⊙. [ABSTRACT FROM AUTHOR]

We use a galaxy sample derived from the Dark Energy Camera Legacy Survey Data Release 9 to measure the baryonic acoustic oscillations (BAO). The magnitude-limited sample consists of 10.6 million galaxies in an area of 4974 deg2 over the redshift range of [0.6, 1]. A key novelty of this work is that the true redshift distribution of the photo- z sample is derived from the self-calibration method, which determines the true redshift distribution using the clustering information of the photometric data alone. Through the angular correlation function in four tomographic bins, we constrain the BAO scale dilation parameter α to be 1.025 ± 0.033, consistent with the fiducial Planck cosmology. Alternatively, the ratio between the comoving angular diameter distance and the sound horizon, D M/ r s, is constrained to be 18.94 ± 0.61 at the effective redshift of 0.749. We corroborate our results with the true redshift distribution obtained from a weighted spectroscopic sample, finding very good agreement. We have conducted a series of tests to demonstrate the robustness of the measurement. Our work demonstrates that the self-calibration method can effectively constrain the true redshift distribution in cosmological applications, especially in the context of photometric BAO measurement. [ABSTRACT FROM AUTHOR]

We present, for the first time, an observational test of the consistency relation for the large-scale structure (LSS) of the Universe through a joint analysis of the anisotropic two- and three-point correlation functions (2PCF and 3PCF) of galaxies. We parameterize the breakdown of the LSS consistency relation in the squeezed limit by Es, which represents the ratio of the coefficients of the shift terms in the second-order density and velocity fluctuations. Es ≠ 1 is a sufficient condition under which the LSS consistency relation is violated. A novel aspect of this work is that we constrain Es by obtaining information about the non-linear velocity field from the quadrupole component of the 3PCF without taking the squeezed limit. Using the galaxy catalogues in the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12, we obtain, indicating that there is no violation of the LSS consistency relation in our analysis within the statistical errors. Our parameterization is general enough that our constraint can be applied to a wide range of theories, such as multicomponent fluids, modified gravity theories, and their associated galaxy bias effects. Our analysis opens a new observational window to test the fundamental physics using the anisotropic higher-order correlation functions of galaxy clustering.

We study the effect of magnification in the Dark Energy Survey Year 3 analysis of galaxy clustering and galaxy-galaxy lensing, using two different lens samples: a sample of luminous red galaxies, redMaGiC, and a sample with a redshift-dependent magnitude limit, MagLim. We account for the effect of magnification on both the flux and size selection of galaxies, accounting for systematic effects using the Balrog image simulations. We estimate the impact of magnification on the galaxy clustering and galaxy-galaxy lensing cosmology analysis, finding it to be a significant systematic for the MagLim sample. We show cosmological constraints from the galaxy clustering autocorrelation and galaxy-galaxy lensing signal with different magnifications priors, finding broad consistency in cosmological parameters in ΛCDM and wCDM. However, when magnification bias amplitude is allowed to be free, we find the two-point correlation functions prefer a different amplitude to the fiducial input derived from the image simulations. We validate the magnification analysis by comparing the cross-clustering between lens bins with the prediction from the baseline analysis, which uses only the autocorrelation of the lens bins, indicating that systematics other than magnification may be the cause of the discrepancy. We show that adding the cross-clustering between lens redshift bins to the fit significantly improves the constraints on lens magnification parameters and allows uninformative priors to be used on magnification coefficients, without any loss of constraining power or prior volume concerns.

We report a new test of modified gravity theories using the large-scale structure of the Universe. This paper is the first attempt to (1) apply a joint analysis of the anisotropic components of galaxy two- and three-point correlation functions (2 and 3PCFs) to actual galaxy data and (2) constrain the non-linear effects of degenerate higher-order scalar-tensor (DHOST) theories on cosmological scales. Applying this analysis to the Baryon Oscillation Spectroscopic Survey (BOSS) data release 12, we obtain the lower bounds of -1.655 < ζt and -0.504 < ζs at the confidence level on the parameters characterizing the time evolution of the tidal and shift terms of the second-order velocity field. These constraints are consistent with GR predictions of ζt = 15/1144 and ζs = 0. Moreover, they represent a 35-fold and 20-fold improvement, respectively, over the joint analysis with only the isotropic 3PCF. We ensure the validity of our results by investigating various quantities, including theoretical models of the 3PCF, window function corrections, cumulative S/N, Fisher matrices, and statistical scattering effects of mock simulation data. We also find statistically significant discrepancies between the BOSS data and the Patchy mocks for the 3PCF measurement. Finally, we package all of our 3PCF analysis codes under the name hitomi and make them publicly available so that readers can reproduce all the results of this paper and easily apply them to ongoing future galaxy surveys.

We cross-correlate positions of galaxies measured in data from the first three years of the Dark Energy Survey with Compton-y maps generated using data from the South Pole Telescope (SPT) and the Planck mission. We model this cross-correlation measurement together with the galaxy autocorrelation to constrain the distribution of gas in the Universe. We measure the hydrostatic mass bias or, equivalently, the mean halo bias-weighted electron pressure (bh Pe), using large-scale information. We find (bh Pe) to be [0.16+−000403, 0.28+−000504, 0.45+−001006, 0.54+−000708, 0.61+−000608, 0.63+−000807] meV cm−3 at redshifts z ∼ [0.30, 0.46, 0.62, 0.77, 0.89, 0.97]. These values are consistent with previous work where measurements exist in the redshift range. We also constrain the mean gas profile using small-scale information, enabled by the high-resolution of the SPT data. We compare our measurements to different parametrized profiles based on the cosmo-OWLS hydrodynamical simulations. We find that our data are consistent with the simulation that assumes an AGN heating temperature of 108.5 K but are incompatible with the model that assumes an AGN heating temperature of 108.0 K. These comparisons indicate that the data prefer a higher value of electron pressure than the simulations within r500c of the galaxies’ haloes.

We measure the tidal alignment of the major axes of luminous red galaxies (LRGs) from the Legacy Imaging Survey and use it to infer the artificial redshift-space distortion signature that will arise from an orientation-dependent, surface-brightness selection in the Dark Energy Spectroscopic Instrument (DESI) survey. Using photometric redshifts to downweight the shape–density correlations due to weak lensing, we measure the intrinsic tidal alignment of LRGs. Separately, we estimate the net polarization of LRG orientations from DESI’s fibre-magnitude target selection to be of order 10-2 along the line of sight. Using these measurements and a linear tidal model, we forecast a 0.5 per cent fractional decrease on the quadrupole of the two-point correlation function for projected separations of 40–80 h-1 Mpc. We also use a halo catalogue from the ABACUSSUMMIT cosmological simulation suite to reproduce this false quadrupole.

We evaluate the consistency between lensing and clustering based on measurements from Baryon Oscillation Spectroscopic Survey combined with galaxy-galaxy lensing from Dark Energy Survey (DES) Year 3, Hyper Suprime-Cam Subaru Strategic Program (HSC) Year 1, and Kilo-Degree Survey (KiDS)-1000. We find good agreement between these lensing data sets. We model the observations using the Dark Emulator and fit the data at two fixed cosmologies: Planck (S8 = 0.83), and a Lensing cosmology (S8 = 0.76). For a joint analysis limited to large scales, we find that both cosmologies provide an acceptable fit to the data. Full utilization of the higher signal-to-noise small-scale measurements is hindered by uncertainty in the impact of baryon feedback and assembly bias, which we account for with a reasoned theoretical error budget. We incorporate a systematic inconsistency parameter for each redshift bin, A, that decouples the lensing and clustering. With a wide range of scales, we find different results for the consistency between the two cosmologies. Limiting the analysis to the bins for which the impact of the lens sample selection is expected to be minimal, for the Lensing cosmology, the measurements are consistent with A = 1; A = 0.91 ± 0.04 (A = 0.97 ± 0.06) using DES+KiDS (HSC). For the Planck case, we find a discrepancy: A = 0.79 ± 0.03 (A = 0.84 ± 0.05) using DES+KiDS (HSC). We demonstrate that a kinematic Sunyaev-Zeldovich-based estimate for baryonic effects alleviates some of the discrepancy in the Planck cosmology. This analysis demonstrates the statistical power of small-scale measurements; however, caution is still warranted given modelling uncertainties and foreground sample selection effects.

The baryon acoustic oscillations (BAOs) phenomenon provides a unique opportunity to establish a standard ruler at any epoch in the history of the evolving universe. The key lies in identifying a suitable cosmological tracer to conduct the measurement. In this study, we focus on quantifying the sound horizon scale of BAO in the Local Universe. Our chosen cosmological tracer is a sample of blue galaxies from the Sloan Digital Sky Survey (SDSS), positioned at the effective redshift |$z_{{\rm eff}} = 0.166$|⁠. Utilizing Planck-CMB input values for redshift-to-distance conversion, we derive the BAO scale |$s_{{\rm BAO}} = 100.28 ^{+10.79} _{-22.96}$| Mpc h −1 at the 1 |$\sigma$| confidence level. Subsequently, we extrapolate the BAO signal scale in redshift space: |$\Delta z_{{\rm BAO}}(z_{\rm eff}=0.166)=0.0361^{+0.00262}_ {-0.0055}$|⁠. This measurement holds the potential to discriminate among dark energy models within the Local Universe. To validate the robustness of our methodology for BAO scale measurement, we conduct three additional BAO analyses using different cosmographic approaches for distance calculation from redshifts. These tests aim to identify possible biases or systematics in our measurements of |$s_{{\rm BAO}}$|⁠. Encouragingly, our diverse cosmographic approaches yield results in statistical agreement with the primary measurement, indicating no significant deviations. Conclusively, our study contributes with a novel determination of the BAO scale in the Local Universe, at |$z_{{\rm eff}} = 0.166$|⁠ , achieved through the analysis of the SDSS blue galaxies cosmic tracer. [ABSTRACT FROM AUTHOR]

The two-point statistics of the cosmic velocity field, measured from galaxy peculiar velocity (PV) surveys, can be used as a dynamical probe to constrain the growth rate of large-scale structures in the Universe. Most works use the statistics on scales down to a few tens of Megaparsecs, while using a theoretical template based on the linear theory. In addition, while the cosmic velocity is volume-weighted, the observable line-of-sight velocity two-point correlation is density-weighted, as sampled by galaxies, and therefore the density–velocity correlation term also contributes, which has often been neglected. These effects are fourth order in powers of the linear density fluctuation |$\delta _{\rm L}^4$|⁠ , compared to |$\delta _{\rm L}^2$| of the linear velocity correlation function, and have the opposite sign. We present these terms up to |$\delta _{\rm L}^4$| in real space based on the standard perturbation theory, and investigate the effect of non-linearity and the density–velocity contribution on the inferred growth rate f σ8, using N -body simulations. We find that for a next-generation PV survey of volume |$\sim {\cal O}(500 \, h^{-1} \, {\rm Mpc})^3$|⁠ , these effects amount to a shift of f σ8 by ∼10 per cent and is comparable to the forecasted statistical error when the minimum scale used for parameter estimation is |$r_{\rm min} = 20 \, h^{-1} \, {\rm Mpc}$|⁠. [ABSTRACT FROM AUTHOR]

Aims. We derived galaxy colour selections from Euclid and ground-based photometry, aiming to accurately define background galaxy samples in cluster weak-lensing analyses. These selections have been implemented in the Euclid data analysis pipelines for galaxy clusters. Methods. Given any set of photometric bands, we developed a method for the calibration of optimal galaxy colour selections that maximises the selection completeness, given a threshold on purity. Such colour selections are expressed as a function of the lens redshift. Results. We calibrated galaxy selections using simulated ground-based griz and EuclidYEJEHE photometry. Both selections produce a purity higher than 97%. The griz selection completeness ranges from 30% to 84% in the lens redshift range zl ∈ [0.2, 0.8]. With the full grizYEJEHE selection, the completeness improves by up to 25 percentage points, and the zl range extends up to zl = 1.5. The calibrated colour selections are stable to changes in the sample limiting magnitudes and redshift, and the selection based on griz bands provides excellent results on real external datasets. Furthermore, the calibrated selections provide stable results using alternative photometric aperture definitions obtained from different ground-based telescopes. The griz selection is also purer at high redshift and more complete at low redshift compared to colour selections found in the literature. We find excellent agreement in terms of purity and completeness between the analysis of an independent, simulated Euclid galaxy catalogue and our calibration sample, except for galaxies at high redshifts, for which we obtain up to 50 percentage points higher completeness. The combination of colour and photo-z selections applied to simulated Euclid data yields up to 95% completeness, while the purity decreases down to 92% at high zl. We show that the calibrated colour selections provide robust results even when observations from a single band are missing from the ground-based data. Finally, we show that colour selections do not disrupt the shear calibration for stage III surveys. The first Euclid data releases will provide further insights into the impact of background selections on the shear calibration. [ABSTRACT FROM AUTHOR]

Estimating a reliable covariance matrix for correlation functions of galaxies is a crucial task to obtain accurate cosmological constraints from galaxy surveys. We generate 2000 independent light-cone mock luminous red galaxy (LRGs) catalogues at 0.3 ≤ z ≤ 1.25, designed to cover CAMIRA LRGs observed by the Subaru Hyper Suprime-Cam Subaru Strategic Programme (HSC SSP). We first produce full-sky light-cone halo catalogues using a COmoving Lagrangian Acceleration (COLA) technique, and then trim them to match the footprints of the HSC SSP S20A Wide layers. The mock LRGs are subsequently populated on to the trimmed halo catalogues according to the halo occupation distribution model constrained by the observed CAMIRA LRGs. The stellar mass (M ⋆) is assigned to each LRG by the subhalo abundance-matching technique using the observed stellar-mass functions of CAMIRA LRGs. We evaluate photometric redshifts (photo- z) of mock LRGs by incorporating the photo- z scatter, which is derived from the observed M ⋆–photo- z -scatter relations of the CAMIRA LRGs. We validate the constructed full-sky halo and light-cone LRG mock catalogues by comparing their angular clustering statistics (i.e. power spectra and correlation functions) with those measured from the halo catalogues of full N -body simulations and the CAMIRA LRG catalogues from the HSC SSP, respectively. We detect clear signatures of baryon acoustic oscillations (BAOs) from our mock LRGs, whose angular scales are well consistent with theoretical predictions. These results demonstrate that our mock LRGs can be used to evaluate covariance matrices at large scales and provide predictions for the BAO detectability and cosmological constraints. [ABSTRACT FROM AUTHOR]

The reconstruction method has been widely employed to improve the baryon acoustic oscillations (BAO) measurement in spectroscopic survey data analysis. In this study, we explore the reconstruction of the BAO signals in the realm of photometric data. By adapting the Zel'dovich reconstruction technique, we develop a formalism to reconstruct the transverse BAO in the presence of photo- z uncertainties under the plane-parallel approximation. We access the performance of the BAO reconstruction through comoving N -body simulations. The transverse reconstruction potential can be derived by solving a 2D potential equation, with the surface density and the radial potential contribution acting as the source terms. The solution is predominantly determined by the surface density. As is evident in dense samples, such as the matter field, the transverse BAO reconstruction can enhance both the strength of the BAO signals and their cross correlation with the initial conditions. At z  = 0, the cross-correlation is increased by a factor of 1.2 at |$k_\perp = 0.2 \, \mathrm{Mpc}^{-1}h$| and 1.4 at |$k_\perp = 0.3 \, \mathrm{Mpc}^{-1}h$|⁠ , respectively. We contrast the 2D potential results with the 3D Poisson equation solution, wherein we directly solve the potential equation using the position in photo- z space, and find good agreement. Additionally, we examine the impact of various conditions, such as the smoothing scales and the level of photo- z uncertainties, on the reconstruction results. We envision the straightforward application of this method to survey data. [ABSTRACT FROM AUTHOR]

We apply the marked correlation function test proposed by Armijo et al. (Paper I) to samples of luminous red galaxies (LRGs) from the final data release of the Sloan Digital Sky Survey (SDSS) III. The test assigns a density-dependent mark to galaxies in the estimation of the projected marked correlation function. Two gravity models are compared: general relativity (GR) and |$f(R)$| gravity. We build mock catalogues which, by construction, reproduce the measured galaxy number density and two-point correlation function of the LRG samples, using the halo occupation distribution model (HOD). A range of HOD models give acceptable fits to the observational constraints, and this uncertainty is fed through to the error in the predicted marked correlation functions. The uncertainty from the HOD modelling is comparable to the sample variance for the SDSS-III LRG samples. Our analysis shows that current galaxy catalogues are too small for the test to distinguish a popular |$f(R)$| model from GR. However, upcoming surveys with a better measured galaxy number density and smaller errors on the two-point correlation function, or a better understanding of galaxy formation, may allow our method to distinguish between viable gravity models. [ABSTRACT FROM AUTHOR]

We investigate dipole asymmetries in four large radio surveys, each spanning more than 75 per cent of the sky. Two of them, the Very Large Array Sky Survey (VLASS) and the Rapid ASKAP Continuum Survey (RACS), have recently yielded dipoles that appear incongruent with each other as well as seem inconsistent with previous radio survey dipoles and the cosmic microwave background (CMB) dipole. Because these radio surveys have large overlaps in sky coverage, comprising hence large majority of common radio sources, one would not expect significant differences between their radio dipoles, irrespective of their underlying source of origin. We examine here in detail these radio dipoles, to ascertain the source of incongruency among them. We find the VLASS and RACS data to be containing some declination-dependent systematics, seemingly in the vicinity of the declination limit of each survey. We show that the effects of such systematics can be mitigated by restricting the declination limits of the respective survey during the dipole determination. A weighted mean of the sky coordinates of thus derived dipoles from the four radio surveys lies within 1.2σ of the CMB dipole direction. However, the amplitude appears significantly larger, 3.7 ± 0.6 times or more than the CMB dipole. This puts in doubt not only the conventional wisdom that the genesis of all these dipoles, including that of the CMB dipole, is due to the Solar peculiar motion, it also raises uncomfortable questions about the Cosmological Principle, the basis of the standard ΛCDM cosmological model. [ABSTRACT FROM AUTHOR]

Peculiar motion of galaxies probes the structure growth in the universe. In this study, we employ the galaxy stellar mass-binding energy (massE) relation with only two nuisance parameters to build the largest peculiar-velocity (PV) catalogue to date, consisting of 229 890 ellipticals from the main galaxy sample (MGS) of the Sloan Digital Sky Survey (SDSS). We quantify the distribution of the massE-based distances in individual narrow redshift bins (dz  = 0.005), and then estimate the PV of each galaxy based on its offset from the Gaussian mean of the distribution. As demonstrated with the Uchuu-SDSS mock data, the derived PV and momentum power spectra are insensitive to accurate calibration of the massE relation itself, enabling measurements out to a redshift of 0.2, well beyond the current limit of z  = 0.1 using other galaxy scaling laws. We then measure the momentum power spectrum and demonstrate that it remains almost unchanged if varying significantly the redshift bin size within which the distance is measured, as well as the intercept and slope of the massE relation, respectively. By fitting the spectra using the perturbation theory model with four free parameters, f σ8 is constrained to f σ8 = 0.459 |$^{+0.068}_{-0.069}$|  over Δ z  = 0.02–0.2, 0.416 |$^{+0.074}_{-0.076}$|  over Δ z  = 0.02–0.1, and 0.526 |$^{+0.133}_{-0.148}$|  over Δ z  = 0.1–0.2. The error of f σ8 is 2.1 times smaller than that by the redshift space distortion (RSD) of the same sample. A Fisher matrix forecast illustrates that the constraint on f σ8 from the massE-based PV can potentially exceed that from the stage-IV RSD in late universe (z <0.5). [ABSTRACT FROM AUTHOR]

We measure the two-point correlation function (CF) of 1357 galaxy clusters with a mass of log10 M 200 ≥ 13.6 h −1 M⊙ and at a redshift of z ≤ 0.125. This work differs from previous analyses in that it utilizes a spectroscopic cluster catalogue, |$\tt {SDSS-GalWCat}$|⁠ , to measure the CF and detect the baryon acoustic oscillation (BAO) signal. Unlike previous studies which use statistical techniques, we compute covariance errors directly by generating a set of 1086 galaxy cluster light-cones from the GLAM N -body simulation. Fitting the CF with a power-law model of the form ξ(s) = (s / s 0)−γ, we determine the best-fitting correlation length and power-law index at three mass thresholds. We find that the correlation length increases with increasing the mass threshold while the power-law index is almost constant. For log10 M 200 ≥ 13.6 h −1 M⊙, we find s 0 = 14.54 ± 0.87 h −1 Mpc and γ = 1.97 ± 0.11. We detect the BAO signal at s  = 100 h −1 Mpc with a significance of 1.60σ. Fitting the CF with a Lambda cold dark matter model, we find |$D_\mathrm{V}(z = 0.089)\mathit{r}^{\mathrm{ fid}}_\mathrm{ d}/\mathit{r}_\mathrm{ d} = 267.62 \pm 26$|   h −1 Mpc, consistent with Planck 2015 cosmology. We present a set of 108 high-fidelity simulated galaxy cluster light-cones from the high-resolution Uchuu N -body simulation, employed for methodological validation. We find D V(z  = 0.089)/ r d = 2.666 ± 0.129, indicating that our method does not introduce any bias in the parameter estimation for this small sample of galaxy clusters. [ABSTRACT FROM AUTHOR]

Using a fully Bayesian approach, Gaussian process regression is extended to include marginalization over the kernel choice and hyperparameters. In addition, Bayesian model comparison via the evidence enables direct kernel comparison. The calculation of the joint posterior was implemented with a transdimensional sampler which simultaneously samples over the discrete kernel choice and their hyperparameters by embedding these in a higher dimensional space, from which samples are taken using nested sampling. Kernel recovery and mean function inference were explored on synthetic data from exoplanet transit light-curve simulations. Subsequently, the method was extended to marginalization over mean functions and noise models and applied to the inference of the present-day Hubble parameter, H 0, from real measurements of the Hubble parameter as a function of redshift, derived from the cosmologically model-independent cosmic chronometer and lambda-cold dark matter-dependent baryon acoustic oscillation observations. The inferred H 0 values from the cosmic chronometers, baryon acoustic oscillations, and combined data sets are |$H_0= 66 \pm 6,\, 67 \pm 10,\, \mathrm{ and}\,69 \pm 6\,\mathrm{km}\, \mathrm{s}^{-1}\, \mathrm{Mpc}^{-1}$|⁠ , respectively. The kernel posterior of the cosmic chronometers data set prefers a non-stationary linear kernel. Finally, the data sets are shown to be not in tension with ln  R = 12.17 ± 0.02. [ABSTRACT FROM AUTHOR]

Galaxy clusters, being the most massive objects in the Universe, exhibit the strongest alignment with the large-scale structure. However, mis-identification of members due to projection effects from the large-scale structure can occur. We studied the impact of projection effects on the measurement of the intrinsic alignment of galaxy clusters, using galaxy cluster mock catalogues. Our findings showed that projection effects result in a decrease of the large-scale intrinsic alignment signal of the cluster and produce a bump at rp ∼ 1 h −1 Mpc, most likely due to interlopers and missed member galaxies. This decrease in signal explains the observed similar alignment strength between bright central galaxies and clusters in the SDSS |$\rm redMaPPer$| cluster catalogue. The projection effect and cluster intrinsic alignment signal are coupled, with clusters having lower fractions of missing members or having higher fraction of interlopers exhibiting higher alignment signals in their projected shapes. We aim to use these findings to determine the impact of projection effects on galaxy cluster cosmology in future studies. [ABSTRACT FROM AUTHOR]

Cross-correlation between weak lensing of the Cosmic Microwave Background (CMB) and weak lensing of galaxies offers a way to place robust constraints on cosmological and astrophysical parameters with reduced sensitivity to certain systematic effects affecting individual surveys. We measure the angular cross-power spectrum between the Atacama Cosmology Telescope (ACT) DR4 CMB lensing and the galaxy weak lensing measured by the Dark Energy Survey (DES) Y3 data. Our baseline analysis uses the CMB convergence map derived from ACT-DR4 and Planck data, where most of the contamination due to the thermal Sunyaev Zel'dovich effect is removed, thus avoiding important systematics in the cross-correlation. In our modelling, we consider the nuisance parameters of the photometric uncertainty, multiplicative shear bias and intrinsic alignment of galaxies. The resulting cross-power spectrum has a signal-to-noise ratio = 7.1 and passes a set of null tests. We use it to infer the amplitude of the fluctuations in the matter distribution (S 8 ≡ σ8(Ωm/0.3)0.5 = 0.782 ± 0.059) with informative but well-motivated priors on the nuisance parameters. We also investigate the validity of these priors by significantly relaxing them and checking the consistency of the resulting posteriors, finding them consistent, albeit only with relatively weak constraints. This cross-correlation measurement will improve significantly with the new ACT-DR6 lensing map and form a key component of the joint 6×2pt analysis between DES and ACT. [ABSTRACT FROM AUTHOR]

We present clustering redshift measurements for Dark Energy Survey (DES) lens sample galaxies used in weak gravitational lensing and galaxy clustering studies. To perform these measurements, we cross-correlate with spectroscopic galaxies from the Baryon Acoustic Oscillation Survey (BOSS) and its extension, eBOSS. We validate our methodology in simulations, including a new technique to calibrate systematic errors that result from the galaxy clustering bias, and we find that our method is generally unbiased in calibrating the mean redshift. We apply our method to the data, and estimate the redshift distribution for 11 different photometrically selected bins. We find general agreement between clustering redshift and photometric redshift estimates, with differences on the inferred mean redshift found to be below |Δz| = 0.01 in most of the bins. We also test a method to calibrate a width parameter for redshift distributions, which we found necessary to use for some of our samples. Our typical uncertainties on the mean redshift ranged from 0.003 to 0.008, while our uncertainties on the width ranged from 4 to 9 per cent. We discuss how these results calibrate the photometric redshift distributions used in companion papers for DES Year 3 results.

We present a Bayesian analysis of the Quaia sample of 1.3 million quasars as a test of the cosmological principle. This principle postulates that the Universe is homogeneous and isotropic on sufficiently large scales, forming the basis of prevailing cosmological models. However, recent analyses of quasar samples have found a matter dipole inconsistent with the inferred kinematic dipole of the cosmic microwave background (CMB), representing a tension with the expectations of the cosmological principle. Here, we explore various hypotheses for the distribution of quasars in Quaia, finding that the sample is influenced by selection effects with significant contamination near the Galactic Plane. After excising these regions, we find significant evidence that the Quaia quasar dipole is consistent with the CMB dipole, both in terms of the expected amplitude and direction. This result is in conflict with recent analyses, lending support to the cosmological principle and the interpretation that the observed dipole is due to our local departure from the Hubble flow. [ABSTRACT FROM AUTHOR]

We explore large-scale cosmic structure using the spatial distribution of 542 gamma-ray bursts (GRBs) having accurately measured positions and spectroscopic redshifts. Prominent cosmological clusters are identified in both the northern and southern galactic hemispheres (avoiding extinction effects in the plane of the Milky Way) using the bootstrap point-radius method. The northern galactic hemisphere contains a significant group of four GRBs in the redshift range 0.59 ≤ z ≤ 0.62 (with a bootstrap probability of p  = 0.012) along with the previously identified Hercules–Corona Borealis Great Wall (in the revised redshift range 0.9 ≤ z ≤ 2.1; p  = 0.017). The southern galactic hemisphere contains the previously identified Giant GRB Ring (p  = 0.022) along with another possible cluster of seven to nine GRBs at 1.17 ≤ z ≤ 1.444 (p  = 0.031). Additionally, both the Hercules–Corona Borealis Great Wall and the Giant GRB Ring have become more prominent as the GRB sample size has grown. The approach used here underscores the potential value of GRB clustering as a probe of large-scale cosmic structure, complementary to galaxy and quasar clustering. Because of the vast scale on which GRB clustering provides valuable insights, it is important that optical GRB monitoring continues so that additional spectroscopic redshift measurements could be obtained. [ABSTRACT FROM AUTHOR]

This is a model-independent analysis that investigates the statistical isotropy in the Local Universe using the Arecibo Legacy Fast ALFA (ALFALFA) survey data (0 < z < 0.06). We investigate the angular distribution of H  i extragalactic sources from the ALFALFA catalogue and study whether they are compatible with the statistical isotropy hypothesis using the two-point angular correlation function (2PACF). Aware that the Local Universe is plenty of clustered structures and large voids, we compute the 2PACF with the Landy–Szalay estimator performing directional analyses to inspect 10 sky regions. We investigate these 2PACF using power-law best-fitting analyses, and determine the statistical significance of the best-fitting parameters for the 10 ALFALFA regions by comparison with the ones obtained through the same procedure applied to a set of mock catalogues produced under the homogeneity and isotropy hypotheses. Our conclusion is that the Local Universe, as mapped by the H  i sources of the ALFALFA survey, is in agreement with the hypothesis of statistical isotropy within |$2\sigma$| confidence level, for small- and large-angle analyses, with the only exception of one region – located near the Dipole Repeller – that appears slightly outlier (⁠|$2.4\sigma$|⁠). Interestingly, regarding the large angular distribution of the H  i sources, we found three regions where the presence of cosmic voids reported in the literature left their signature in our 2PACF, suggesting projected large underdensities there, with number-density contrast δ ≃ −0.7. According to the current literature, these regions correspond, partially, to the sky position of the void structures known as Local Cosmic Void and Dipole Repeller. [ABSTRACT FROM AUTHOR]

We perform the weak lensing mass mapping analysis to identify troughs , which are defined as local minima in the mass map. Since weak lensing probes the projected matter distribution along the line of sight, these troughs can be produced by single or multiple voids projected along the line of sight. To scrutinize the origins of the weak lensing troughs, we systematically investigate the line-of-sight structure of troughs selected from the latest Subaru Hyper Suprime-Cam (HSC) Year 3 weak lensing data covering |$433.48 \, \mathrm{deg}^2$|⁠. From a curved sky mass map constructed with the HSC data, we identify 15 troughs with the signal-to-noise ratio higher than 5.7 and address their line-of-sight density structure utilizing redshift distributions of two galaxy samples, photometric luminous red galaxies observed by HSC and spectroscopic galaxies detected by Baryon Oscillation Spectroscopic Survey. While most weak lensing signals due to the troughs are explained by multiple voids aligned along the line of sight, we find that two of the 15 troughs potentially originate from single voids at redshift ∼0.3. The single void interpretation appears to be consistent with our three-dimensional mass mapping analysis. We argue that single voids can indeed reproduce observed weak lensing signals at the troughs if these voids are not spherical but are highly elongated along the line-of-sight direction. [ABSTRACT FROM AUTHOR]

We investigate the main tensions within the current standard model of cosmology from the perspective of the main statistics of cosmic voids, using the final BOSS DR12 data set. For this purpose, we present the first estimate of the S8 ≡ σ8 Ωm/0.3 and H0 parameters obtained from void number counts and shape distortions. To analyze void counts we relied on an extension of the popular volume-conserving model for the void size function, tailored to the application on data, including geometric and dynamic distortions. We calibrated the two nuisance parameters of this model with the official BOSS Collaboration mock catalogs and propagated their uncertainty through the statistical analysis of the BOSS void number counts. The constraints from void shapes come from the study of the geometric distortions of the stacked void-galaxy cross-correlation function. In this work we focus our analysis on the Ωm − σ8 and Ωm − H0 parameter planes and derive the marginalized constraints S8 = 0.813−0.068+0.093 and H0 = 67.3−9.1+10.0 km s−1 Mpc−1, which are fully compatible with constraints from the literature. These results are expected to notably improve in precision when analyzed jointly with independent probes and will open a new viewing angle on the rising cosmological tensions in the near future. [ABSTRACT FROM AUTHOR]

An accurate reconstruction of galaxy cluster masses is key to use this population of objects as a cosmological probe. In this work we present a study on the hydrostatic-to-lensing mass scaling relation for a sample of 53 clusters whose masses were reconstructed homogeneously in a redshift range between z = 0.05 and 1.07. The M500 mass for each cluster was indeed inferred from the mass profiles extracted from the X-ray and lensing data, without using a priori observable-mass scaling relations. We assessed the systematic dispersion of the masses estimated with our reference analyses with respect to other published mass estimates. Accounting for this systematic scatter does not change our main results, but enables the propagation of the uncertainties related to the mass reconstruction method or used dataset. Our analysis gives a hydrostatic-to-lensing mass bias of (1−b) = 0.739−0.070+0.075 and no evidence of evolution with redshift. These results are robust against possible subsample differences. [ABSTRACT FROM AUTHOR]

Context. The Euclid mission of the European Space Agency will perform a survey of weak lensing cosmic shear and galaxy clustering in order to constrain cosmological models and fundamental physics. Aims. We expand and adjust the mock Euclid likelihoods of the MontePython software in order to match the exact recipes used in previous Euclid Fisher matrix forecasts for several probes: weak lensing cosmic shear, photometric galaxy clustering, the cross-correlation between the latter observables, and spectroscopic galaxy clustering. We also establish which precision settings are required when running the Einstein–Boltzmann solvers CLASS and CAMB in the context of Euclid. Methods. For the minimal cosmological model, extended to include dynamical dark energy, we perform Fisher matrix forecasts based directly on a numerical evaluation of second derivatives of the likelihood with respect to model parameters. We compare our results with those of previously validated Fisher codes using an independent method based on first derivatives of the Euclid observables. Results. We show that such MontePython forecasts agree very well with previous Fisher forecasts published by the Euclid Collab oration, and also, with new forecasts produced by the CosmicFish code, now interfaced directly with the two Einstein–Boltzmann solvers CAMB and CLASS. Moreover, to establish the validity of the Gaussian approximation, we show that the Fisher matrix marginal error contours coincide with the credible regions obtained when running Monte Carlo Markov chains with MontePython while using the exact same mock likelihoods. Conclusions. The new Euclid forecast pipelines presented here are ready for use with additional cosmological parameters, in order to explore extended cosmological models. [ABSTRACT FROM AUTHOR]

We provide a measurement of the deficit in the Sunyaev–Zel'dovich Compton- y signal towards cosmic voids, by stacking a catalogue of 97 090 voids constructed with BOSS-DR12 data, on the y -maps built on data from the Atacama Cosmology Telescope (ACT) DR4 and the Planck satellite. We detect the void signal with a significance of |$7.3 \sigma$| with ACT and |$9.7\sigma$| with Planck , obtaining agreements in the associated void radial y -profiles extracted from both maps. The inner-void profile (for angular separations within the void angular radius) is reconstructed with significances of 4.7σ and 6.1σ with ACT and Planck , respectively; we model such profile using a simple model that assumes uniform gas (under)density and temperature, which enables us to place constraints on the product (−δv T e) of the void density contrast (negative) and the electron temperature. The best-fitting values from the two data sets are |$(-\delta _{\rm v}T_{\rm e})=(6.5\pm 2.3)\times 10^{5}\, \text{K}$| for ACT and |$(8.6 \pm 2.1)\times 10^{5}\, \text{K}$| for Planck [68 per cent confidence level (CL)], which are in good agreement under uncertainty. The data allow us to place lower limits on the expected void electron temperature at |$2.7\times 10^5\, \text{K}$| with ACT and |$5.1\times 10^5\, \text{K}$| with Planck (95 per cent CL); these results can transform into upper limits for the ratio between the void electron density and the cosmic mean as |$n^{\rm v}_{\rm e}/\bar{n}_{\rm e}\leqslant 0.73$| and 0.49 (95 per cent CL), respectively. Our findings prove the feasibility of using thermal Sunyaev–Zel'dovich observations to constrain the gas properties inside cosmic voids, and confirm that voids are under-pressured regions compared to their surroundings. [ABSTRACT FROM AUTHOR]

In addition to the intrinsic clustering of galaxies themselves, the spatial distribution of galaxies observed in surveys is modulated by the presence of weak lensing due to matter in the foreground. This effect, known as magnification bias, is a significant contaminant to analyses of galaxy-lensing cross-correlations and must be carefully modelled. We present a method to estimate the magnification bias in spectroscopically confirmed galaxy samples based on finite differences of galaxy catalogues while marginalizing over errors due to finite step size. We use our estimator to measure the magnification biases of the CMASS and LOWZ samples in the SDSS BOSS galaxy survey, analytically taking into account the dependence on galaxy shape for fibre and PSF magnitudes, finding αCMASS = 2.71 ± 0.02 and αLOWZ = 2.45 ± 0.02 and quantify modelling uncertainties in these measurements. Finally, we quantify the redshift evolution of the magnification bias within the CMASS and LOWZ samples, finding a difference of up to a factor of three between the lower and upper redshift bounds for the former. We discuss how to account for this evolution in modelling and its interaction with commonly applied redshift-dependent weights. Our method should be readily applicable to upcoming surveys and we make our code publicly available as part of this work. [ABSTRACT FROM AUTHOR]

We carry out a statistical analysis of the spatial distribution of galaxies at cosmological redshifts 0.16 ≤ z ≤ 0.47 based on the SDSS DR12 LOWZ catalogue. Our aim is to search and study possible large-scale quasi-regular structures embedded in the cosmic web. We calculate projections of the Cartesian galaxy coordinates on different axes (directions), densely covering certain regions in the sky to look for special directions along which 1D distributions of the projections contain significant quasi-periodic components. These components appear as peaks in the power spectra and lie in a narrow range of wave numbers 0.05 < k < 0.07. Particular attention is paid to the evaluation of the significance of the peaks. It is found that the significance of the dominant peaks for some selected directions exceeds (4–5)σ. In order to reduce possible selection effects, we create a mock homogeneous catalogue of spatial distribution of galaxies by adding a random set of artificial objects (points) to the real galaxies under study. The power spectrum of this cumulative model data also demonstrates significant peak corresponding to approximately the same scale. As a result we assume the existence of an anisotropic cosmological quasi-periodic structure with characteristic scale (116 ± 10)  h −1 Mpc. [ABSTRACT FROM AUTHOR]

The dark ages 21-cm signal is a powerful tool for precision cosmology and probing new physics. We study two non-standard models: an excess radio background (ERB) model (possibly generated by dark matter decay) and the millicharged dark matter (mDM) model. These models were inspired by the possible EDGES detection of a strong global 21-cm absorption during cosmic dawn, but more generally they provide a way to anticipate the potential discovery space. During the dark ages the 21-cm global signal in the ERB model reaches a saturated form for an amplitude A r = 0.4, where A r is the radio background intensity at cosmic dawn relative to the cosmic microwave background. This amplitude is one fifth of the minimum required to explain the EDGES signal, and corresponds to just 0.1 per cent of the observed extragalactic background; it would give a signal that can be detected at 5.9σ significance (compared to 4.1σ for the standard signal) and can be distinguished from the standard (no ERB) signal at 8.5σ, all with a 1000 h global signal measurement. The 21-cm power spectrum has potentially more information, but far greater resources would be required for comparable constraints. For the mDM model, over a range of viable parameters, the global signal detection significance would be |$4.7-7.2\, \sigma$|⁠ , and it could be distinguished from standard at |$2.2-9.3\, \sigma$|⁠. With an array of global signal antennas achieving an effective 100 000 h integration, the significance would be 10× better. Our analysis helps motivate the development of lunar and space-based dark ages experiments. [ABSTRACT FROM AUTHOR]

We explore possible signatures of the interaction between dark matter (DM) and massive neutrinos during the post-reionization epoch. Using both Fisher matrix forecast analysis and Markov chain Monte Carlo simulation, we conduct a thorough investigation of the constraints and imprints of the scenario on the upcoming post-reionization and galaxy surveys. Our investigation focuses on two key parameters: the strength of the DM–massive neutrino interaction (u) and the total neutrino mass (M tot), on top of the usual six cosmological parameters. We utilize future 21-cm intensity mapping, galaxy clustering, and cosmic shear observations in order to investigate the possible constraints of these parameters in the future observations: Square Kilometre Array (SKA1 and SKA2) and Euclid, taking both conservative and realistic approaches. All these missions show promise in constraining both the parameters u and M tot by few orders compared to the current constraints from Planck18 (SKA2 performing the best among them). Although we do not find much improvement in H 0 and σ8 tensions from our forecast analysis, SKA2 constrains them better in conservative approach. We further perform a brief investigation of the prospects of some of the next-generation cosmic microwave background (CMB) missions in combinations with large-scale structure experiments in improving the constraints. Our analysis reveals that both SKA2 and CMB-S4 (Cosmic Microwave Background Stage-4) + Euclid + SKA1 IM2 (Square Kilometre Array1 Intensity Mapping Band2) combination will put the strongest bounds on the model parameters. [ABSTRACT FROM AUTHOR]