http://arxiv.org/abs/2305.13836

This paper is the third in a series on submillimeter galaxy magnification bias, focusing on the tomographic scenario. It refines the methodology used to constrain the halo occupation distribution model and cosmological parameters within a flat $\Lambda$CDM model, using updated data. The study aims to optimize CPU time, explore strategies for analyzing different redshift bins, and assess the impact of excluding the GAMA15 field. The tomographic approach involves dividing the redshift range into bins and analyzing cross-correlation measurements between submillimeter and foreground galaxies. The results show good agreement between the mean-redshift and full model cases, with an increase in the minimum mass of lenses at higher redshifts. The inferred cosmological parameters have narrower posterior distributions, indicating reduced measurement uncertainties compared to previous studies. Excluding the GAMA15 field reduces the cross-correlation signal, suggesting sample variance within the large-scale structure. Extending the redshift range improves robustness against sample variance and produces similar but tighter constraints. The study highlights the importance of sample variance and redshift binning in tomographic analyses, and suggests using additional wide-area fields and updated foreground catalogues for more effective implementation.

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L. Bonavera, M. Cueli, J. González-Nuevo, et. al.
Wed, 24 May 23
81/81

Comments: This work is the third of a series of three. 17 pages and 19 figure. submitted to A&A

http://arxiv.org/abs/2305.11956

One important source of systematics in galaxy redshift surveys comes from the estimation of the galaxy window function. Up until now, the impact of the uncertainty in estimating the galaxy window function on parameter inference has not been properly studied. In this paper, we show that the uncertainty and the bias in estimating the galaxy window function will be salient for ongoing and next-generation galaxy surveys using a simulation-based approach. With a specific case study of cross-correlating Emission-line galaxies from the DESI Legacy Imaging Surveys and the Planck CMB lensing map, we show that neural network-based regression approaches to modelling the window function are superior in comparison to linear regression-based models. We additionally show that the definition of the galaxy overdensity estimator can impact the overall signal-to-noise of observed power spectra. Finally, we show that the additive biases coming from the window functions can significantly bias the modes of the inferred parameters and also degrade their precision. Thus, a careful understanding of the window functions will be essential to conduct cosmological experiments.

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T. Karim, M. Rezaie, S. Singh, et. al.
Tue, 23 May 23
77/77

Comments: 13 pages, 12 figures, complementary paper to an upcoming paper on Cross-Correlation of ELGs and Planck CMB lensing

http://arxiv.org/abs/2305.11396

The main aim of this paper is to present the multi scalar field components as candidates to be the dark energy of the universe and their observational constraints. We start with the canonical Quintessence and Phantom fields with quadratic potentials and show that a more complex model should bear in mind to satisfy current cosmological observations. Then we present some implications for a combination of two fields, named as Quintom models. We consider two types of models, one as the sum of the quintessence and phantom potentials and other including an interacting term between fields. We find that adding one degree of freedom, by an interacting term, the dynamics enriches considerably and could lead to an improvement in the fit of $-2\ln\Delta \Like_{\rm max}= 5.13$, compared to $\Lambda$CDM. The resultant effective equation of state is now able to cross the phantom divide line, and in several cases present an oscillatory or discontinuous behavior, depending on the interaction value. The parameter constraints of the scalar field models (quintessence, phantom, quintom and interacting quintom) were performed using Cosmic Chronometers, Supernovae Ia and Baryon Acoustic Oscillations data; and the Log-Bayes factors were computed to compare the performance of the models. We show that single scalar fields may face serious troubles and hence the necessity of a more complex models, i.e. multiple fields.

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J. Vázquez, D. Tamayo, G. Garcia-Arroyo, et. al.
Mon, 22 May 23
8/60

Comments: 17 pages, 8 figures

http://arxiv.org/abs/2305.11431

We develop a deep learning technique to reconstruct the dark matter density field from the redshift-space distribution of dark matter halos. We implement a UNet-architecture neural network and successfully trained it using the COLA fast simulation, which is an approximation of the N-body simulation with $512^3$ particles in a box size of $500 h^{-1}{\rm {Mpc}}$. We evaluate the resulting UNet model not only using the training-like test samples, but also using the typical N-body simulations, including the Jiutian simulation which has $6144^3$ particles in a box size of $1000 h^{-1}{\rm {Mpc}}$, and the ELUCID simulation which has a different cosmology. The real-space dark matter density fields in the three simulations can all be recovered consistently with only a small reduction of the cross-correlation power spectrum at 1\% and 10\% levels at $k=0.1$ and $0.3~h\mathrm{Mpc^{-1}}$, respectively. It is evident that the reconstruction helps to correct for the redshift-space distortions and is unaffected by the different cosmologies between the training sample ({\bf Planck2018}) and the test sample ({\bf WMAP5}). In addition, we tested the application of the UNet-reconstructed density field to recover the velocity \& tidal field and found it outperforms the traditional approach based on the linear bias model, showing a 12.2 percent improvement in the correlation slope and a 21.1 percent reduction in the scatter between the predicted and the true velocities. As a result, our method is highly efficient and has an outstanding level of extrapolation reliability beyond the training set. This offers an optimal solution that determines the three-dimensional underlying density field from the abundant galaxy survey data.

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Z. Wang, F. Shi, X. Yang, et. al.
Mon, 22 May 23
10/60

Comments: 14 pages, 16 figures

http://arxiv.org/abs/2305.10487

Interloper contamination due to line misidentification is an important issue in the future low-resolution spectroscopic surveys. We realize that the algorithm previously used for photometric redshift self-calibration, with minor modifications, can be particularly applicable to calibrate the interloper bias. In order to explore the robustness of the modified self-calibration algorithm, we construct the mock catalogues based on China Space Station Telescope (CSST), taking two main target emission lines, H$\alpha$ and [O III]. The self-calibration algorithm is tested in cases with different interloper fractions at 1 per cent, 5 per cent and 10 per cent. We find that the interloper fraction and mean redshift in each redshift bin can be successfully reconstructed at the level of ~ 0.002 and ~ 0.001(1+z), respectively. We also find the impact of the cosmic magnification can be significant, which is usually ignored in previous works, and therefore propose a convenient and efficient method to eliminate it. Using the elimination method, we show that the calibration accuracy can be effectively recovered with slightly larger uncertainty.

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H. Peng and Y. Yu
Fri, 19 May 23
11/46

Comments: 9 pages, 9 figures, submitted to MNRAS

http://arxiv.org/abs/2305.10597

We study signatures of primordial non-Gaussianity (PNG) in the redshift-space halo field on non-linear scales, using a combination of three summary statistics, namely the halo mass function (HMF), power spectrum, and bispectrum. The choice of adding the HMF to our previous joint analysis of power spectrum and bispectrum is driven by a preliminary field-level analysis, in which we train graph neural networks on halo catalogues to infer the PNG $f_\mathrm{NL}$ parameter. The covariance matrix and the responses of our summaries to changes in model parameters are extracted from a suite of halo catalogues constructed from the Quijote-PNG N-body simulations. We consider the three main types of PNG: local, equilateral and orthogonal. Adding the HMF to our previous joint analysis of power spectrum and bispectrum produces two main effects. First, it reduces the equilateral $f_\mathrm{NL}$ predicted errors by roughly a factor $2$, while also producing notable, although smaller, improvements for orthogonal PNG. Second, it helps break the degeneracy between the local PNG amplitude, $f_\mathrm{NL}^\mathrm{local}$, and assembly bias, $b_{\phi}$, without relying on any external prior assumption. Our final forecasts for PNG parameters are $\Delta f_\mathrm{NL}^\mathrm{local} = 40$, $\Delta f_\mathrm{NL}^\mathrm{equil} = 210$, $\Delta f_\mathrm{NL}^\mathrm{ortho} = 91$, on a cubic volume of $1 \left( {\rm Gpc}/{\rm h} \right)^3$, with a halo number density of $\bar{n}\sim 5.1 \times 10^{-5}~h^3\mathrm{Mpc}^{-3}$, at $z = 1$, and considering scales up to $k_\mathrm{max} = 0.5~h\,\mathrm{Mpc}^{-1}$.

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G. Jung, A. Ravenni, M. Baldi, et. al.
Fri, 19 May 23
13/46

Comments: 17 pages, 11 figures

http://arxiv.org/abs/2305.09827

Weak galaxy lensing surveys have consistently reported low values of the $S_8$ parameter compared to the $\textit{Planck}\ \Lambda\rm{CDM}$ cosmology. Amon & Efstathiou (2022) used KiDS-1000 cosmic shear measurements to propose that this tension can be reconciled if the matter fluctuation spectrum is suppressed more strongly on non-linear scales than assumed in state-of-the-art hydrodynamical simulations. In this paper, we investigate cosmic shear data from the Dark Energy Survey (DES) Year 3. The non-linear suppression of the matter power spectrum required to resolve the $S_8$ tension between DES and the $\textit{Planck}\ \Lambda\rm{CDM}$ model is not as strong as inferred using KiDS data, but is still more extreme than predictions from recent numerical simulations. An alternative possibility is that non-standard dark matter contributes to the required suppression. We investigate the redshift and scale dependence of the suppression of the matter power spectrum. If our proposed explanation of the $S_8$ tension is correct, the required suppression must extend into the mildly non-linear regime to wavenumbers $k\sim 0.2 h {\rm Mpc}^{-1}$. In addition, all measures of $S_8$ using linear scales should agree with the $\textit{Planck}\ \Lambda\rm{CDM}$ cosmology, an expectation that will be testable to high precision in the near future.

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C. Preston, A. Amon and G. Efstathiou
Thu, 18 May 23
4/67

Comments: 12 pages, 9 figures

http://arxiv.org/abs/2305.10340

Ultralight dark matter (ULDM) is an interesting alternative to the cold dark matter (CDM) paradigm. Due to the extremely low mass of the constituent particle ($\sim 10^{-22}$ eV), ULDM can exhibit quantum effects up to kiloparsec scales. In particular, runaway collapse in the centres of ULDM halos is prevented by quantum pressure, providing a possible resolution to the ‘core-cusp problem’ of CDM. However, the the detailed relationship between the ULDM core mass and that of the overall halo is poorly understood. We simulate the collapse of both spherical and aspherical isolated ULDM overdensities using AxioNyx, finding that the central cores of collapsed halos undergo sustained oscillatory behaviour which affects both their peak density and overall morphology. The variability in core morphology increases with the asphericity of the initial overdensity and remnants of initial asphericity persist long after collapse. Furthermore, the peak central densities are higher in spherical configurations. Consequently, astrophysically realistic halos may exhibit substantial departures from theoretical core-halo profiles and we would expect a significant variance of the properties of halos with the same mass.

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E. Kendall, M. Gosenca and R. Easther
Thu, 18 May 23
10/67

Comments: 11 pages, 11 figures

http://arxiv.org/abs/2305.09733

We study the redshift evolution of the baryon budget in a large set of galaxy clusters from the {\it Magneticum} suite of SPH cosmological simulations. At high redshifts, we obtain “closed box” systems independently by the mass of the systems on radii greater than $3R_{500,\mathrm c}$, whereas at lower redshifts, only the most massive halos could be considered as `”closed box”. The baryon fraction shows a general decrease with the redshift and, for less massive objects, we observe a much more prominent decrease than for massive halos. The gas depletion parameter $Y_{\rm gas}$ shows a steeper and highly scattered radial distribution in the central regions of less massive halos with respect to massive objects at all redshifts, while on larger radii the gas fraction distributions are independent of the masses or the redshifts. The hot component of the gas traces well the total amount of gas at low redshifts. At higher redshifts, the cold component provides a not negligible contribution to the total amount of baryon in our systems. Moreover, the behaviour of the baryonic, entire gas, and hot gas phase depletion parameters as a function of radius, mass, and redshift are described by some functional forms. The evolution of metallicity and stellar mass in halos suggests that the early enrichment process is dominant. We investigate correlations between the time evolution of AGN feedback and the depletion parameters. We demonstrate that the energy injected by the AGN activity shows a particularly strong positive correlation with $Y_{\rm bar}$, $Y_{\rm cold}$,$Y_{\rm star}$ and a negative one with $Y_{\rm hot}$, $Z_{\rm Tot}$. These trends are consistent with previous works, meaning that our results, combined with findings derived from current and future X-rays observations, represent possible proxies to test the AGN feedback models used in different suites of numerical simulations.

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M. Angelinelli, S. Ettori, K. Dolag, et. al.
Thu, 18 May 23
34/67

Comments: Accepted in A&A, 15 pages, 11 figures

http://arxiv.org/abs/2305.10315

The Weakly Interacting Massive Particles(WIMPs) have long been the favored CDM candidate in the standard $\Lambda$CDM model. However, owing to great improvement in the experimental sensitivity in the past decade, some parameter space of the SUSY-based WIMP model is ruled out. In addition, WIMP as the CDM particle is also at variance with other astrophysical observables at small scales. We consider a model that addresses both these issues. In the model, the WIMP decays into a massive particle and radiation. We study the background evolution and the first order perturbation theory (coupled Einstein-Boltzmann equations) for this model and show that the dynamics can be captured by a single parameter $r=m_L/q$, which is the ratio of the lighter mass and the comoving momentum of the decay particle. We incorporate the relevant equations in the existing Boltzmann code CLASS to compute the matter power spectra and CMB angular power spectra. The decaying WIMP model is akin to a non-thermal Warm Dark Matter(WDM) model and suppresses matter power at small scales, which could alleviate several issues that plague the CDM model. We compare the predictions of the model with CMB, galaxy clustering, and high-z HI data. Both these data sets yield $r\gtrsim 10^6$, which can be translated into the bounds on other parameters. In particular, we obtain the following lower bounds on the self-annihilation cross-section of WIMPs $\sigma$, and the lighter mass $m_L$: $\sigma\gtrsim 5\times 10^{-44}\,\rm cm^2$ and $m_L\gtrsim 2.4\,\rm keV$. The lower limit on $m_L$ is comparable to constraints on the mass of thermally-produced WDM particle. The limit on the self-annihilation cross-section greatly expands the available parameter space as compared to the stable WIMP scenario.

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A. Parichha and S. Sethi
Thu, 18 May 23
41/67

Comments: 24 pages (main text 17 pages), 7 figures, 2 tables

http://arxiv.org/abs/2305.10193

Taking advantage of the reduced levels of noise and systematics in the data of the latest Planck release (PR4, also known as NPIPE), we construct a new all-sky Compton-$y$ parameter map (hereafter, $y$-map) of the thermal Sunyaev-Zeldovich (SZ) effect from the Planck PR4 data. A tailored Needlet Internal Linear Combination (NILC) pipeline, first validated on detailed sky simulations, is applied to the nine single-frequency Planck PR4 sky maps, ranging from $30$ to $857$ GHz, to produce the PR4 $y$-map over 98% of the sky. Using map comparisons, angular power spectra and one-point statistics we show that the PR4 NILC $y$-map is of improved quality compared to that of the previous PR2 release. The new $y$-map shows reduced levels of large-scale striations associated with $1/f$ noise in the scan direction. Regions near the Galactic plane also show lower residual contamination by Galactic thermal dust emission. At small angular scales, the residual contamination by thermal noise and cosmic infrared background (CIB) emission is found to be reduced by around 7% and 34%, respectively, in the PR4 $y$-map. The PR4 NILC $y$-map is made publicly available for astrophysical and cosmological analyses of the thermal SZ effect.

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J. Chandran, M. Remazeilles and R. Barreiro
Thu, 18 May 23
54/67

Comments: 17 pages, 17 figures, submitted to MNRAS

http://arxiv.org/abs/2305.09882

The thermal Sunyaev-Zel’dovich (tSZ) effect is a spectral distortion of the cosmic microwave background (CMB) resulting from inverse Compton scattering of CMB photons with electrons in the medium of galaxy clusters. The spectrum of the tSZ effect is typically calculated assuming the spectrum of the CMB is a blackbody. However, energy or photon number injection at any epoch after photon creation processes become inefficient will distort the blackbody, potentially leading to a chemical potential or $\mu$-distortion for early injection. These $primordial$ spectral distortions will therefore introduce a change in the tSZ effect, effectively a distortion of a distortion. While this effect is small for an individual cluster’s spectrum, upcoming and proposed CMB surveys expect to detect tens of thousands of clusters with the tSZ effect. In this paper, we forecast constraints on the $\mu$-distortion monopole from the distortion of the tSZ spectrum of clusters measured by CMB surveys. We find that planned experiments have the raw sensitivity to place constraints on $\mu$ that are comparable to or better than existing constraints but control over foregrounds and other systematics will be critical.

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D. Zegeye, T. Crawford and W. Hu
Thu, 18 May 23
56/67

Comments: 15 pages, 5 figures

http://arxiv.org/abs/2305.09888

We identify cosmic voids from galaxy density fields under the theory of void-cluster correspondence. We extend the previous novel void-identification method developed for the matter density field to the galaxy density field for practical applications. From cosmological N-body simulations, we construct galaxy number- and mass-weighted density fields to identify cosmic voids that are counterparts of galaxy clusters of specific mass. The parameters for the cluster-counterpart void identification such as Gaussian smoothing scale, density threshold, and core volume fraction are found for galaxy density fields. We achieve about $60$–$67\%$ of completeness and reliability for identifying the voids of corresponding cluster mass above $3\times10^{14}h^{-1}M_{\odot}$ from a galaxy sample with the mean number density, $\bar{n}=4.4\times10^{-3} (h^{-1}{\rm Mpc})^{-3}$. When the mean density is increased to $\bar{n}=10^{-2} (h^{-1}{\rm Mpc})^{-3}$, the detection rate is enhanced by $\sim2$–$7\%$ depending on the `mass scale’ of voids. We find that the detectability is insensitive to the density weighting scheme applied to generate the density field. Our result demonstrates that we can apply this method to the galaxy redshift survey data to identify cosmic voids corresponding statistically to the galaxy clusters in a given mass range.

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J. Shim, C. Park, J. Kim, et. al.
Thu, 18 May 23
61/67

Comments: 10 pages, 5 figures, 1 table. Accepted for publication in ApJ

http://arxiv.org/abs/2305.09075

The primary purpose of this work is the provision of accurate, analytic, evolutionary templates for cosmological parameters and fundamental constants in a dynamical cosmology. A flat quintessence cosmology with a dark energy potential that has the mathematical form of the Higgs potential is the specific cosmology and potential addressed in this work. These templates, based on the physics of the cosmology and potential are intended to replace the parameterizations currently used to determine the likelihoods of dynamical cosmologies. Acknowledging that, unlike {\Lambda}CDM, the evolutions are dependent on both the specific cosmology and the dark energy potential the templates are referred to as Specific Cosmology and Potential, SCP, templates. The requirements set for the SCP templates are that they must be accurate, analytic functions of an observable such as the scale factor or redshift. This is achieved through the utilization of a modified beta function formalism that is based on a physically motivated dark energy potential to calculate the beta function. The methodology developed here is designed to be adaptable to other cosmologies and dark energy potentials. The SCP templates are essential tools in determining the relative likelihoods of a range of dynamical cosmologies and potentials. An ultimate purpose is the determination whether dark energy is dynamical or static in a quantitative manner. It is suggested that the SCP templates calculated in this work can serve as fiducial dynamical templates in the same manner as {\Lambda}CDM serves for static dark energy.

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R. Thompson
Wed, 17 May 23
7/67

Comments: Published in the Journal Universe

http://arxiv.org/abs/2305.08931

It has been pointed out that the spurious Cosmic Microwave Background (CMB) B-mode polarization signals caused by the absorption of the CMB monopole component due to the Galactic interstellar matter, called the CMB shadow, degrade the accuracy of detecting the CMB B-mode polarization signals imprinted by primordial gravitational waves. We have made a realistic estimation using simulated sky maps of how the CMB shadow affects forthcoming high-precision CMB B-mode experiments for the first time. The Delta-map method, an internal template method taking into account the first-order spatial variation of foregrounds’ spectral parameters, is applied as a foreground removal method. We show that if the CMB shadow effects are not taken into account in the foreground removal process, future observations would lead to the false detection of the CMB B-mode polarization signals originating from primordial gravitational waves. We also show that the effect of the CMB shadow can be mitigated by our revised Delta-map method to target the CMB B-mode polarization signals at the level of tensor-to-scalar ratio r=0.001.

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T. Murokoshi, Y. Chinone, M. Nashimoto, et. al.
Wed, 17 May 23
17/67

Comments: 8 pages, 2 figures, Accepted for publication in ApJL

http://arxiv.org/abs/2305.09337

Perturbation theory is a powerful tool for studying large-scale structure formation in the universe and calculating observables such as the power spectrum or bispectrum. However, beyond linear order, typically this is done by assuming a simplification in the time-dependence of gravitational-coupling kernels between the matter and velocity fluctuations. Though the true dependencies are known for Lambda cold dark matter cosmologies, they are ignored due to the computational costs associated with considering them in full and, instead, are replaced by simpler dependencies valid for an Einstein–de-Sitter cosmology. Here we develop, implement and demonstrate the effectiveness of a new numerical method for finding the full dynamical evolution of these kernels to all perturbative orders based upon spectral methods using Chebyshev polynomials. This method is found to be orders of magnitude more efficient than direct numerical solvers while still producing highly accurate and reliable results. A code implementation of the Chebyshev spectral method is then presented and characterised. The code has been made publicly available alongside this paper. We expect our method to be of use for interpretation of upcoming galaxy clustering measurements.

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N. Choustikov, Z. Vlah and A. Challinor
Wed, 17 May 23
31/67

Comments: 18 pages, 9 figures, 1 table, submitted to PRD

http://arxiv.org/abs/2305.08899

The full-shape correlations of the Lyman alpha (Ly$\alpha$) forest contain a wealth of cosmological information through the Alcock-Paczy\'{n}ski effect. However, these measurements are challenging to model without robustly testing and verifying the theoretical framework used for analyzing them. Here, we leverage the accuracy and volume of the $N$-body simulation suite \textsc{AbacusSummit} to generate high-resolution Ly$\alpha$ skewers and quasi-stellar object (QSO) catalogs. One of the main goals of our mocks is to aid in the full-shape Ly$\alpha$ analysis planned by the Dark Energy Spectroscopic Instrument (DESI) team. We provide optical depth skewers for six of the fiducial cosmology base-resolution simulations ($L_{\rm box} = 2\,h^{-1}{\rm Gpc}$, $N = 6912^3$) at $z = 2.5$. We adopt a simple recipe based on the Fluctuating Gunn-Peterson Approximation (FGPA) for constructing these skewers from the matter density in an $N$-body simulation and calibrate it against the 1D and 3D Ly$\alpha$ power spectra extracted from the hydrodynamical simulation IllustrisTNG (TNG; $L_{\rm box} = 205\,h^{-1}{\rm Mpc}$, $N = 2500^3$). As an important application, we study the non-linear broadening of the baryon acoustic oscillation (BAO) peak and show the cross-correlation between DESI-like QSOs and our Ly$\alpha$ forest skewers. We find differences on small scales between the Kaiser approximation prediction and our mock measurements of the Ly$\alpha$$\times$QSO cross-correlation, which would be important to account for in upcoming analyses. The \textsc{AbacusSummit} Ly$\alpha$ forest mocks open up the possibility for improved modelling of cross correlations between Ly$\alpha$ and cosmic microwave background (CMB) lensing and Ly$\alpha$ and QSOs, and for forecasts of the 3-point Ly$\alpha$ correlation function. Our catalogues and skewers are publicly available on Globus.

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B. Hadzhiyska, A. Font-Ribera, A. Cuceu, et. al.
Wed, 17 May 23
42/67

Comments: 17 pages, 8 figures, Globus link: this https URL&path=%2F

http://arxiv.org/abs/2305.09367

In the expanding Universe, the dimensional quantities like the wavelength and the temperature of photons are cosmologically redshifted by the relative difference between the observed and emitted ones. Therefore, it can be physically meaningful to talk about the constancy or variability of any dimensional constant (not only of dimensionless one) when the Universe is expanding. It has been known that one can measure the temporal variation of the fine structure constant $\alpha$ in the emission and absorption lines of quasar spectra when the speed of light varies for cosmic time, even though this statement is model dependent. Current observations based on the alkali doublet method and on the many-multiplet one show superficially contradictory results. The former finds no statistically significant evidence for a time dependence of $\alpha$, while the latter does. The so-called meVSL model can reconcile these results naturally without any contradiction.

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S. Lee
Wed, 17 May 23
55/67

Comments: 10 pages

http://arxiv.org/abs/2305.08903

We develop an optimization-based maximum likelihood approach to analyze the cross-correlation of the Cosmic Microwave Background (CMB) and large-scale structure induced by the kinetic Sunyaev-Zeldovich (kSZ) effect. Our main goal is to reconstruct the radial velocity field of the universe. While the existing quadratic estimator (QE) is statistically optimal for current and near-term experiments, the likelihood can extract more signal-to-noise in the future. Our likelihood formulation has further advantages over the QE, such as the possibility of jointly fitting cosmological and astrophysical parameters and the possibility of unifying several different kSZ analyses. We implement an auto-differentiable likelihood pipeline in JAX, which is computationally tractable for a realistic survey size and resolution, and evaluate it on the Agora simulation. We also implement a machine learning-based estimate of the electron density given an observed galaxy distribution, which can increase the signal-to-noise for both the QE and the likelihood method.

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Y. Kvasiuk and M. Münchmeyer
Wed, 17 May 23
61/67

Comments: 26 pages, 9 figures

http://arxiv.org/abs/2305.08843

We investigate the properties of dark energy halos in models with a nonminimal coupling in the dark sector. We show, using a quasistatic approximation, that a coupling of the mass of dark matter particles to a standard quintessence scalar field $\phi$ generally leads to the formation of dark energy concentrations in and around compact dark matter objects. These are associated with regions where scalar field gradients are large and the dark energy equation of state parameter is close to $-1/3$. We find that the energy and radius of a dark energy halo are approximately given by $E_{\rm halo} \sim \boldsymbol{\beta}^2 \varphi \, m$ and $r_{\rm halo} \sim \sqrt{\boldsymbol{\beta} \,\varphi ({R}/{H})}$, where $\varphi=Gm/(R c^2)$, $m$ and $R$ are, respectively, the mass and radius of the associated dark matter object, $\boldsymbol{\beta} = -d \ln m/d \phi$ is the nonminimal coupling strength parameter, $H$ is the Hubble parameter, $G$ is the gravitational constant, and $c$ is the speed of light in vacuum. We further show that current observational limits on $\boldsymbol{\beta}$ over a wide redshift range lead to stringent constraints on $E_{\rm halo}/m$ and, therefore, on the impact of dark energy halos on the value of the dark energy equation of state parameter. We also briefly comment on potential backreaction effects that may be associated with the breakdown of the quasistatic approximation and determine the regions of parameter space where such a breakdown might be expected to occur.

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P. Avelino
Tue, 16 May 23
53/83

Comments: 6 pages, Physical Review D (in press)

http://arxiv.org/abs/2305.08593

The 21-cm signal from the dark ages provides a potential new probe of fundamental cosmology. While exotic physics could be discovered, here we quantify the expected benefits within the standard cosmology. A measurement of the global (sky-averaged) 21-cm signal to the precision of thermal noise from a 1,000 hour integration would yield a $5.5\%$ measurement of a combination of cosmological parameters. A 10,000 hour integration would improve this to $1.8\%$, and constrain the cosmic Helium fraction as well as Planck. Precision cosmology with 21-cm fluctuations requires a collecting area of $10\,{\rm km}^2$ (which corresponds to 400,000 stations), which with a 1,000 hour integration would exceed the same global case. Enhancing the collecting area or integration time $\times$10 would yield a $0.5\%$ parameter combination, a Helium measurement five times better than Planck, and a constraint on the neutrino mass as good as Planck. Our analysis sets a baseline for upcoming lunar and space-based dark ages experiments.

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R. Mondal and R. Barkana
Tue, 16 May 23
54/83

Comments: 30 pages, 3 (+ 5 in the appendix) figures

http://arxiv.org/abs/2305.07046

Recent observations of radio relics – diffuse radio emission in galaxy clusters – have revealed that these sources are not smooth but consist of structures in the form of threads and filaments. We investigate the origin of these filamentary structures and the role of projection effects. To this end, we have developed a tool that extracts the filamentary structures from background emission. Moreover, it is capable of studying both two-dimensional and three-dimensional objects. We apply our structure extractor to, both, observations and cosmological simulations of radio relics. Using Minkowski functionals, we determine the shape of the identified structures. In our 2D analysis, we find that the brightest structures in the observed and simulated maps are filaments. Our analysis of the 3D simulation data shows that radio relics do not consist of sheets but only of filaments and ribbons. Furthermore, we did not find any measurable projection effects that could hide any sheet-like structures in projection. We find that, both, the magnetic field and the shock front consist of filaments and ribbons that cause filamentary radio emission.

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D. Wittor, M. Brüggen, P. Grete, et. al.
Mon, 15 May 23
28/53

Comments: 20 pages, 22 figures, accepted for publication in MNRAS

http://arxiv.org/abs/2305.07650

We detect the cross-correlation between 2.7 million DESI quasar targets across 14,700 deg$^2$ (180 quasars deg$^{-2}$) and Planck 2018 CMB lensing at $\sim$30$\sigma$. We use the cross-correlation on very large scales to constrain local primordial non-Gaussianity via the scale dependence of quasar bias. The DESI quasar targets lie at an effective redshift of 1.51 and are separated into four imaging regions of varying depth and image quality. We select quasar targets from Legacy Survey DR9 imaging, apply additional flux and photometric redshift cuts to improve the purity and reduce the fraction of unclassified redshifts, and use early DESI spectroscopy of 194,000 quasar targets to determine their redshift distribution and stellar contamination fraction (2.6%). Due to significant excess large-scale power in the quasar autocorrelation, we apply weights to mitigate contamination from imaging systematics such as depth, extinction, and stellar density. We use realistic contaminated mocks to determine the greatest number of systematic modes that we can fit, before we are biased by overfitting and spuriously remove real power. We find that linear regression with one to seven imaging templates removed per region accurately recovers the input cross-power, $f_{\textrm{NL}}$ and linear bias. As in previous analyses, our $f_{\textrm{NL}}$ constraint depends on the linear primordial non-Gaussianity bias parameter, $b_{\phi} = 2(b – p)\delta_c$ assuming universality of the halo mass function. We measure $f_{\textrm{NL}} = -26^{+45}{-40}$ with $p=1.6$ $(f{\textrm{NL}} = -18^{+29}{-27}$ with $p=1.0$), and find that this result is robust under several systematics tests. Future spectroscopic quasar cross-correlations with Planck lensing lensing can tighten the $f{\textrm{NL}}$ constraints by a factor of 2 if they can remove the excess power on large scales in the quasar auto power spectrum.

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A. Krolewski, W. Percival, S. Ferraro, et. al.
Mon, 15 May 23
34/53

Comments: 57 pages, 25 figures, submitted to JCAP

http://arxiv.org/abs/2305.06771

We present a novel test of the cosmological principle: the idea that, on sufficiently large scales, the universe should appear homogeneous and isotropic to observers comoving with the Hubble flow. This is a fundamental assumption in modern cosmology, underpinning the use of the Friedmann-Lema\^itre-Robertson-Walker metric as part of the concordance $\Lambda$CDM paradigm. However, the observed dipole imprinted on the Cosmic Microwave Background (CMB) is interpreted as our departure from the Hubble flow, and such a proper motion will induce a directionally-dependent time dilation over the sky. We illustrate the feasibility of detection of this ‘time dilation dipole’ and sketch the practical steps involved in its extraction from a catalogue of sources with intrinsic time-scales. In essence, whilst the scale of this dilation is small, being of order of 0.1%, it will in principle be detectable in large scale surveys of variable cosmological sources, such as quasars and supernovae. The degree of alignment of the time dilation dipole with the kinematic dipole derived from the CMB will provide a new assessment of the cosmological principle, and address the tension in dipole measures from other observations.

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O. Oayda and G. Lewis
Fri, 12 May 23
4/53

Comments: 9 pages, 4 figures, accepted for publication in MNRAS

http://arxiv.org/abs/2305.06792

The kinematic and thermal Sunyaev-Zel’dovich (kSZ and tSZ) effects probe the abundance and thermodynamics of ionized gas in galaxies and clusters. We present a new hybrid estimator to measure the kSZ effect by combining cosmic microwave background temperature anisotropy maps with photometric and spectroscopic optical survey data. The method interpolates a velocity reconstruction from a spectroscopic catalog at the positions of objects in a photometric catalog, which makes it possible to leverage the high number density of the photometric catalog and the precision of the spectroscopic survey. Combining this hybrid kSZ estimator with a measurement of the tSZ effect simultaneously constrains the density and temperature of free electrons in the photometrically selected galaxies. Using the 1000 deg2 of overlap between the Atacama Cosmology Telescope (ACT) Data Release 5, the first three years of data from the Dark Energy Survey (DES), and the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12, we detect the kSZ signal at 4.8${\sigma}$ and reject the null (no-kSZ) hypothesis at 5.1${\sigma}$. This corresponds to 2.0${\sigma}$ per 100,000 photometric objects with a velocity field based on a spectroscopic survey with 1/5th the density of the photometric catalog. For comparison, a recent ACT analysis using exclusively spectroscopic data from BOSS measured the kSZ signal at 2.1${\sigma}$ per 100,000 objects. Our derived constraints on the thermodynamic properties of the galaxy halos are consistent with previous measurements. With future surveys, such as the Dark Energy Spectroscopic Instrument and the Rubin Observatory Legacy Survey of Space and Time, we expect that this hybrid estimator could result in measurements with significantly better signal-to-noise than those that rely on spectroscopic data alone.

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M. Mallaby-Kay, S. Amodeo, J. Hill, et. al.
Fri, 12 May 23
11/53

Comments: 19 pages, 15 figures

http://arxiv.org/abs/2305.06367

The gravitationally lensed Supernova Refsdal appeared in multiple images, produced through gravitational lensing by a massive foreground galaxy cluster. After the supernova appeared in 2014, lens models of the galaxy cluster predicted an additional image of the supernova would appear in 2015, which was subsequently observed. We use the time delays between the images to perform a blinded measurement of the expansion rate of the Universe, quantified by the Hubble constant (H0). Using eight cluster lens models, we infer H0 = 64.8 +4.4-4.3 km / s / Mpc, where Mpc is the megaparsec. Using the two models most consistent with the observations, we find H0 = 66.6 +4.1-3.3 km / s / Mpc. The observations are best reproduced by models that assign dark-matter halos to individual galaxies and the overall cluster.

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P. Kelly, S. Rodney, T. Treu, et. al.
Fri, 12 May 23
14/53

Comments: Published in Science. Companion paper presenting time-delay and relative magnification measurements published in ApJ (DOI: 10.3847/1538-4357/ac4ccb)

http://arxiv.org/abs/2305.06514

Due to the non-linear ionizing and heating processes, the 21-cm signals from epoch of reionization (EoR) are expected to have strong non-Gaussian fluctuations. In this paper, we use the semi-numerical simulations to study the non-Gaussian statistics i.e. skew spectrum and smoothed skewness of the 21-cm signals from EoR. We find the 21-cm skew spectrum and smoothed skewness have similar evolution features with the 21-cm bispectrum. All of them are sensitive to the EoR models, while not too much to the cosmic volume applied. With the SKA1-low telescope as reference, we find both the skew spectrum and smoothed skewness have much higher S/N ratios than the 21-cm bispectrum.

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Q. Ma and L. Peng
Fri, 12 May 23
22/53

Comments: 7 pages, 5 figures, mnras accepted

http://arxiv.org/abs/2305.07018

We study the use of U-Nets in reconstructing the linear dark matter density field and its consequences for constraining cosmological parameters, in particular primordial non-Gaussianity. Our network is able to reconstruct the initial conditions of redshift $z=0$ density fields from N-body simulations with $90\%$ accuracy out to $k \leq 0.4$ h/Mpc, competitive with state-of-the-art reconstruction algorithms at a fraction of the computational cost. We study the information content of the reconstructed $z=0$ density field with a Fisher analysis using the QUIJOTE simulation suite, including non-Gaussian initial conditions. Combining the pre- and post-reconstructed power spectrum and bispectrum data up to $k_{\rm max} = 0.52$ h/Mpc, we find significant improvements on all parameters. Most notably, we find a factor $3.65$ (local), $3.54$ (equilateral) and $2.90$ (orthogonal) improvement on the marginalized errors of $f_{\rm NL}$ as compared to only using the pre-reconstructed data. We show that these improvements can be attributed to a combination of reduced data covariance and parameter degeneracy. The results constitute an important step towards more optimal inference of primordial non-Gaussianity from non-linear scales.

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T. Flöss and P. Meerburg
Fri, 12 May 23
25/53

Comments: 22 pages, 8 figures, 3 tables, codes available at this https URL and this https URL

http://arxiv.org/abs/2305.07022

The Macquart relation describes the correlation between the dispersion measure (DM) of fast radio bursts (FRBs) and the redshift $z$ of their host galaxies. The scatter of the Macquart relation is sensitive to the distribution of baryons in the intergalactic medium (IGM) including those ejected from galactic halos through feedback processes. The width of the distribution in DMs from the cosmic web (${\rm DM}{\rm cosmic}$) is parameterized by a fluctuation parameter $F$, which is related to the cosmic DM variance by $\sigma{\rm DM}= F z^{-0.5}$. In this work, we present a new measurement of $F$ using 78 FRBs of which 21 have been localized to host galaxies. Our analysis simultaneously fits for the Hubble constant $H_0$ and the DM distribution due to the FRB host galaxy. We find that the fluctuation parameter is degenerate with these parameters, most notably $H_0$, and use a uniform prior on $H_0$ to measure $\log_{10} F > -0.89$ at the $3\sigma$ confidence interval and a new constraint on the Hubble constant $H_0 = 85.3_{-8.1}^{+9.4} \, {\rm km \, s^{-1} \, Mpc^{-1}}$. Using a synthetic sample of 100 localized FRBs, the constraint on the fluctuation parameter is improved by a factor of $\sim 2$. Comparing our $F$ measurement to simulated predictions from cosmological simulation (IllustrisTNG), we find agreement between $0.4 < z < 2$. However, at $z < 0.4$, the simulations underpredict $F$ which we attribute to the rapidly changing extragalactic DM excess distribution at low redshift.

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J. Baptista, J. Prochaska, A. Mannings, et. al.
Fri, 12 May 23
45/53

Comments: Submitted to ApJ. 11 pages, 9 figures, 4 tables

http://arxiv.org/abs/2305.06377

In late 2014, four images of Supernova (SN) “Refsdal,” the first known example of a strongly lensed SN with multiple resolved images, were detected in the MACS J1149 galaxy-cluster field. Following the images’ discovery, the SN was predicted to reappear within hundreds of days at a new position ~8 arcseconds away in the field. The observed reappearance in late 2015 makes it possible to carry out Refsdal’s (1964) original proposal to use a multiply imaged SN to measure the Hubble constant H0, since the time delay between appearances should vary inversely with H0. Moreover, the position, brightness, and timing of the reappearance enable a novel test of the blind predictions of galaxy-cluster models, which are typically constrained only by the positions of multiply imaged galaxies. We have developed a new photometry pipeline that uses DOLPHOT to measure the fluxes of the five images of SN Refsdal from difference images. We apply four separate techniques to perform a blind measurement of the relative time delays and magnification ratios (mu_i/mu_1) between the last image SX and the earlier images S1-S4. We measure the relative time delay of SX-S1 to be 376.0+5.6-5.5 days and the relative magnification to be 0.30+0.05-0.03. This corresponds to a 1.5% precision on the time delay and 17% precision for the magnification ratios, and includes uncertainties due to millilensing and microlensing. In an accompanying paper, we place initial and blind constraints on the value of the Hubble constant.

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P. Kelly, S. Rodney, T. Treu, et. al.
Fri, 12 May 23
48/53

Comments: Published in ApJ. Companion paper presenting H0 constraints published in Science (DOI: 10.1126/science.abh1322)

http://arxiv.org/abs/2305.05790

The galaxy cluster Zwicky 3146 is a sloshing cool core cluster at $z{=}0.291$ that in SZ imaging does not appear to exhibit significant pressure substructure in the intracluster medium (ICM). We perform a surface brightness fluctuation analysis via Fourier amplitude spectra on SZ (MUSTANG-2) and X-ray (XMM-Newton) images of this cluster. These surface brightness fluctuations can be deprojected to infer pressure and density fluctuations from the SZ and X-ray data, respectively. In the central region (Ring 1, $r < 100^{\prime\prime} = 440$ kpc, in our analysis) we find fluctuation spectra that suggest injection scales around 200 kpc ($\sim 140$ kpc from pressure fluctuations and $\sim 250$ kpc from density fluctuations). When comparing the pressure and density fluctuations in the central region, we observe a change in the effective thermodynamic state from large to small scales, from isobaric (likely due to the slow sloshing) to adiabatic (due to more vigorous motions). By leveraging scalings from hydrodynamical simulations, we find an average 3D Mach number $\approx0.5$. We further compare our results to other studies of Zwicky 3146 and, more broadly, to other studies of fluctuations in other clusters.

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C. Romero, M. Gaspari, G. Schellenberger, et. al.
Thu, 11 May 23
33/55

Comments: Accepted to ApJ; 22 pages, 19 figures

http://arxiv.org/abs/2305.06326

Galaxy clusters induce a distinct dipole pattern in the cosmic microwave background (CMB) through the effect of gravitational lensing. Extracting this lensing signal will enable us to constrain cluster masses, even for high redshift clusters ($z \gtrsim 1$) that are expected to be detected by future CMB surveys. However, cluster-correlated foreground signals, like the kinematic and thermal Sunyaev-Zel’dovich (kSZ and tSZ) signals, present a challenge when extracting the lensing signal from CMB temperature data. While CMB polarization-based lensing reconstruction is one way to mitigate these foreground biases, the sensitivity from CMB temperature-based reconstruction is expected to be similar to or higher than polarization for future surveys. In this work, we extend the cluster lensing estimator developed in Raghunathan et al. (2019) to CMB temperature and test its robustness against systematic biases from foreground signals. We find that the kSZ signal only acts as an additional source of variance and provide a simple stacking-based approach to mitigate the bias from the tSZ signal. Additionally, we study the bias induced due to uncertainties in the cluster positions and show that they can be easily mitigated. The estimated signal-to-noise ratio (SNR) of this estimator is comparable to other standard lensing estimators such as the maximum likelihood (MLE) and quadratic (QE) estimators. We predict the cluster mass uncertainties from CMB temperature data for current and future cluster samples to be: 6.6% for SPT-3G with 7,000 clusters, 4.1% for SO and 3.9% for SO + FYST with 25,000 clusters, and 1.8% for CMB-S4 with 100,000 clusters.

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K. Levy, S. Raghunathan and K. Basu
Thu, 11 May 23
40/55

Comments: 22 pages, 7 figures, 2 tables; to be submitted to JCAP; comments welcome

http://arxiv.org/abs/2305.05696

We present the first hydrodynamical cosmological simulations in the $\nu$HDM framework based on Milgromian dynamics (MOND) with light (11~eV) sterile neutrinos. $\nu$HDM can explain the expansion history, CMB anisotropies, and galaxy cluster dynamics similarly to standard cosmology while preserving MOND’s successes on galaxy scales, making this the most conservative Milgromian framework. We generate initial conditions including sterile neutrinos using \textsc{camb} and \textsc{music} and modify the publicly available code \textsc{phantom of ramses} to run $\nu$HDM models. The simulations start at redshift $z_e=199$, when the gravitational fields are stronger than $a_{_0}$ provided this does not vary. We analyse the growth of structure and investigate the impact of resolution and box size, which is at most 600 comoving Mpc. Large density contrasts arise at late times, which may explain the KBC void and Hubble tension. We quantify the mass function of formed structures at different redshifts. We show that the sterile neutrino mass fraction in these structures is similar to the cosmic fraction at high masses (consistent with MOND dynamical analyses) but approaches zero at lower masses, as expected for galaxies. We also identify structures with a low peculiar velocity comparable to the Local Group, but these are rare. The onset of group/cluster scale structure formation at $z_e\approx4$ appears to be in tension with observations of high redshift galaxies, which we discuss in comparison to prior analytical work in a MONDian framework. The formation of a cosmic web of filaments and voids demonstrates that this is not unique to standard Einstein/Newton-based cosmology.

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N. Wittenburg, P. Kroupa, I. Banik, et. al.
Thu, 11 May 23
48/55

Comments: 24 pages, 11 figures, 3 tables; accepted for publication in MNRAS 28.04.2023; For movies of the models simulated in this work see this https URL

http://arxiv.org/abs/2305.04959

An ionization front (I-front) that propagates through an inhomogeneous medium is slowed down by self-shielding and recombinations. We perform cosmological radiation hydrodynamics simulations of the I-front propagation during the epoch of cosmic reionization. The simulations resolve gas in minihalos (halo mass $10^4\lesssim M_h[{\rm M}\odot]\lesssim 10^8)$ that could dominate recombinations, in a computational volume that is large enough to sample the abundance of such halos. The numerical resolution is sufficient (gas particle mass $\sim 20{\rm M}\odot$, spatial resolution $< 0.1\;{\rm ckpc}$) to allow accurate modelling of the hydrodynamic response of gas to photo-heating. We quantify the photo-evaporation time of minihalos as a function of $M_h$ and its dependence on the photo-ionization rate, $\Gamma_{-12}$, and the redshift of reionization, $z_i$. The recombination rate can be enhanced over that of a uniform medium by a factor $\sim 10-20$ early on. The peak value increases with $\Gamma_{-12}$ and decreases with $z_i$, due to the enhanced contribution from minihalos. The clumping factor, $c_r$, decreases to a factor of a few at $\sim 100\;{\rm Myr}$ after the passage of the I-front when the minihalos have been photo-evaporated; this asymptotic value depends only weakly on $\Gamma_{-12}$. Recombinations increase the required number of photons per baryon to reionize the Universe by 20-100 per cent, with the higher value occurring when $\Gamma_{-12}$ is high and $z_i$ is low. We complement the numerical simulations with simple analytical models for the evaporation rate and the inverse Str\”omgren layer. The study also demonstrates the proficiency and potential of SPHM1RT to address astrophysical problems in high-resolution cosmological simulations.

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T. Chan, A. Benitez-Llambay, T. Theuns, et. al.
Wed, 10 May 23
54/65

Comments: 34 pages, 34 figures; submitted to MNRAS

http://arxiv.org/abs/2305.04564

Many galaxy clusters show diffuse cluster-scale emission in the form of radio halos, showing that magnetic fields and relativistic electrons are mixed in with the intra-cluster medium (ICM). There is general agreement that the origin of radio halos is connected to turbulence, generated during cluster mergers. Statistical studies of large samples of galaxy clusters in the radio band have the potential to unveil the connection between the properties of radio halos and the mass and dynamics of the host clusters. Previous studies have been limited to massive clusters and based on a small number of radio halos. The aim of this paper is to investigate the scaling relation between the radio power of radio halos and the mass of the host clusters at low frequencies and down to lower cluster masses. We analysed the clusters from the second catalogue of Planck Sunyaev Zel’dovich sources that lie within the 5634 sq deg covered by the second Data Release of the LOFAR Two-meter Sky Survey. We derived the correlation between the radio power and the mass of the host clusters and we investigated the distribution of clusters without radio halos with respect to the correlation. We use X-ray observations to classify the dynamical state of clusters and investigate its role on the power of radio halos. We found a correlation between the power of radio halos at 150 MHz and the mass of the host clusters down to 3e14 Msun. This correlation has a large scatter, part of which can be attributed to the different dynamical states of host clusters. We used two statistical test to show that the distribution of clusters with and without (upper limits) radio halos in the mass-radio power diagram is not compatible with a single correlation and that it is also not compatible with clusters being uniformly distributed below an upper envelope constituted by the correlation.

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V. Cuciti, R. Cassano, M. Sereno, et. al.
Tue, 9 May 23
3/88

Comments: 12 pages, 7 figures, submitted to A&A

http://arxiv.org/abs/2305.04752

Dark energy is believed to be responsible for the acceleration of the universe. In this paper, we reconstruct the dark energy scalar field potential $V(\phi)$ using the Hubble parameter H(z) through Gaussian Process analysis. Our goal is to investigate dark energy using various H(z) datasets and priors. We find that the choice of prior has little effect on the reconstructed $V(\phi)$, but the choice of H(z) dataset has a significant impact. Our result shows that Observational H(z) data (OHD) produces better results in reconstructing $V(\phi)$ compared to cosmic chronometers (CC). Additionally, we simulate H(z) data to measure the effect of increasing the number of data points on the accuracy of reconstructed $V(\phi)$. We find that doubling the number of H(z) data points can improve the accuracy rate of reconstructed $V(\phi)$ by 5$\%$ to 30$\%$.

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J. Niu, Y. Chen and T. Zhang
Tue, 9 May 23
25/88

Comments: 13 pages, 9 figures, 3 tables

http://arxiv.org/abs/2305.04028

The power spectrum and bispectrum of dark matter tracers are key and complementary probes of the Universe. Next-generation surveys will deliver good measurements of the bispectrum, opening the door to improved cosmological constraints and the breaking of parameter degeneracies, from the combination of the power spectrum and bispectrum. Multi-tracer power spectra have been used to suppress cosmic variance and mitigate the effects of nuisance parameters and systematics. We present a bispectrum multi-tracer formalism that can be applied to next-generation survey data. Then we perform a simple Fisher analysis to illustrate qualitatively the improved precision on primordial non-Gaussianity that is expected to come from the bispectrum multi-tracer. In addition, we investigate the parametric dependence of conditional errors from multi-tracer power spectra and multi-tracer bispectra, on the differences between the biases and the number densities of two tracers. Our results suggest that optimal constraints arise from maximising the ratio of number densities, the difference between the linear biases, the difference between the quadratic biases, and the difference between the products $b_1\,b_\Phi$ for each tracer, where $b_\Phi$ is the bias for the primordial potential.

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D. Karagiannis, R. Maartens, J. Fonseca, et. al.
Tue, 9 May 23
47/88

Comments: 27 pages, 6 figures, to be submitted on JCAP

http://arxiv.org/abs/2305.03976

The weak gravitational lensing is a powerful tool in modern cosmology. To accurately measure the weak lensing signal, one has to control the systematic bias to a small level. One of the most difficult problems is how to correct the smearing effect of the Point Spread Function (PSF) on the shape of the galaxies. The chromaticity of PSF for a broad-band observation can lead to new subtle effects. Since the PSF is wavelength dependent and the spectrum energy distributions between stars and galaxies are different, the effective PSF measured from the star images will be different from that smears the galaxies. Such a bias is called colour bias. We estimate it in the optical bands of the Chinese Space Station Survey Telescope from simulated PSFs, and show the dependence on the colour and redshift of the galaxies. Moreover, due to the spatial variation of spectra over the galaxy image, there exists another higher-order bias, colour gradient bias. Our results show that both colour bias and colour gradient bias are generally below $0.1$ percent in CSST. Only for small-size galaxies, one needs to be careful about the colour gradient bias in the weak lensing analysis using CSST data.

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Q. Liu, X. Er, Z. Fan, et. al.
Tue, 9 May 23
61/88

Comments: N/A

http://arxiv.org/abs/2305.04520

Modifications in the law of gravity can leave signatures on the large-scale structure, especially on the non-linear and quasi-linear scales. In this work, we propose that the four Minkowski functionals (MFs), which fully encapsulate the morphological information of the large-scale structure, are a powerful tool to constrain modified gravity(MG). With the assistance of N-body simulations, we quantify the MFs’ constraining power on the Hu-Sawicki $f(R)$ gravity model by the Fisher matrix technique. The cosmic variance from the finite simulation volume is discussed. By measuring the MFs from the density field of dark matter with different smoothing scales and at different redshifts, we systematically evaluate how much information can be extracted from the MFs in these situations, and try to combine them to improve the constraint. Furthermore, we study the MG signatures imprinted in the MFs of the large-scale structures (LSS) when the biased tracer — dark matter halo — is used. And find the response to the fifth force is different from the matter. We also study how the constraints on modified gravity parameters change when using biased tracers of LSS. We expect that the MFs of LSS can provide us with a stringent constraint on modified gravity in the near future.

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A. Jiang, W. Liu, B. Li, et. al.
Tue, 9 May 23
67/88

Comments: 23 pages, 7 figures, prepared for JCAP

http://arxiv.org/abs/2305.03082

We investigate the statistical properties and the origin of the scatter within the spatially resolved surface brightness profiles of the CHEX-MATE sample, formed by 118 galaxy clusters selected via the SZ effect. These objects have been drawn from the Planck SZ catalogue and cover a wide range of masses, M${500}=[2-15] \times 10^{14} $M${\odot}$, and redshift, z=[0.05,0.6]. We derived the surface brightness and emission measure profiles and determined the statistical properties of the full sample. We found that there is a critical scale, R$\sim 0.4 R_{500}$, within which morphologically relaxed and disturbed object profiles diverge. The median of each sub-sample differs by a factor of $\sim 10$ at $0.05\,R_{500}$. There are no significant differences between mass- and redshift-selected sub-samples once proper scaling is applied. We compare CHEX-MATE with a sample of 115 clusters drawn from the The Three Hundred suite of cosmological simulations. We found that simulated emission measure profiles are systematically steeper than those of observations. For the first time, the simulations were used to break down the components causing the scatter between the profiles. We investigated the behaviour of the scatter due to object-by-object variation. We found that the high scatter, approximately 110%, at $R<0.4R_{500}$ is due to a genuine difference between the distribution of the gas in the core. The intermediate scale, $R_{500} =[0.4-0.8]$, is characterised by the minimum value of the scatter on the order of 0.56, indicating a region where cluster profiles are the closest to the self-similar regime. Larger scales are characterised by increasing scatter due to the complex spatial distribution of the gas. Also for the first time, we verify that the scatter due to projection effects is smaller than the scatter due to genuine object-by-object variation in all the considered scales. [abridged]

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I. Bartalucci, S. Molendi, E. Rasia, et. al.
Mon, 8 May 23
29/63

Comments: Accepted for publication in A&A

http://arxiv.org/abs/2305.03070

We implement a novel formalism to constrain primordial non-Gaussianity of the local type from the large-scale modulation of the small-scale power spectrum. Our approach combines information about primordial non-Gaussianity contained in the squeezed bispectrum and the collapsed trispectrum of large-scale structure together in a computationally amenable and consistent way, while avoiding the need to model complicated covariances of higher $N$-point functions. This work generalizes our recent work, which used a neural network estimate of local power, to the more conventional local power spectrum statistics, and explores using both matter field and halo catalogues from the Quijote simulations. We find that higher $N$-point functions of the matter field can provide strong constraints on $f_{NL}$, but higher $N$-point functions of the halo field, at the halo density of Quijote, only marginally improve constraints from the two-point function.

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U. Giri, M. Münchmeyer and K. Smith
Mon, 8 May 23
60/63

Comments: 14 pages, 7 figures

http://arxiv.org/abs/2305.02490

Primordial B-mode detection is one of the main goals of next-generation cosmic microwave background (CMB) experiments. Primordial B-modes are a unique signature of primordial gravitational waves (PGWs). However, the gravitational interaction of CMB photons with large-scale structures will distort the primordial E modes, adding a lensing B-mode component to the primordial B-mode signal. Removing the lensing effect (`delensing’) from observed CMB polarization maps will be necessary to improve the constraint of PGWs and obtain a primordial E-mode signal. Here, we introduce a deep convolutional neural network model named multi-input multi-output U-net (MIMO-UNet) to perform CMB delensing. The networks are trained on simulated CMB maps with size $20^{\circ} \times 20^{\circ}$. We first use MIMO-UNet to reconstruct the unlensing CMB polarization ($Q$ and $U$) maps from observed CMB maps. The recovered E-mode power spectrum exhibits excellent agreement with the primordial EE power spectrum. The recovery of the primordial B-mode power spectrum for noise levels of 0, 1, and 2 $\mu$K-arcmin is greater than 98\% at the angular scale of $\ell<150$. We additionally reconstruct the lensing B map from observed CMB maps. The recovery of the lensing B-mode power spectrum is greater than roughly 99\% at the scales of $\ell>200$. We delens observed B-mode power spectrum by subtracting reconstructed lensing B-mode spectrum. The recovery of tensor B-mode power spectrum for noise levels of 0, 1, 2 $\mu$K-arcmin is greater than 98 \% at the angular scales of $\ell<120$. Even at $\ell=160$, the recovery of tensor B-mode power spectrum is still around 71 \%.

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Y. Yan, G. Wang, S. Li, et. al.
Fri, 5 May 23
1/67

Comments: 18 pages, 14 figures, 1 table, accepted by ApJS

http://arxiv.org/abs/2305.02339

This article delivers the dynamical cosmography of the Local Universe within z=0.1 (1 giga light-years). We exploit the gravitational velocity field computed using the CosmicFlows-4 catalog of galaxy distances to delineate superclusters as watersheds, publishing for the first time their size, shape, main streams of matter and the location of their central attractor. Laniakea, our home supercluster’s size is confirmed to be 2 $\times 10^6$ (Mpc $h^{-1}$)$^3$. Five more superclusters are now dynamically revealed in the same way: Apus, Hercules, Lepus, Perseus-Pisces and Shapley. Also, the central repellers of the Bootes and Sculptor voids are found and the Dipole and Cold Spot repellers now appear as a single gigantic entity. Interestingly the observed superclusters are an order of magnitude larger than the theoretical ones predicted by cosmological $\Lambda$CDM simulations.

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A. Dupuy and H. Courtois
Fri, 5 May 23
3/67

Comments: 8 pages, 4 figures, 1 table, submitted to A&A (AA/2023/46802)

http://arxiv.org/abs/2305.02430

Observations support the idea that supermassive black holes (SMBHs) power the emission at the center of active galaxies. However, contrary to stellar-mass BHs, there is a poor understanding of their origin and physical formation channel. In this article, we propose a new process of SMBH formation in the early Universe that is not associated with baryonic matter (massive stars) or primordial cosmology. In this novel approach, SMBH seeds originate from the gravitational collapse of fermionic dense dark matter (DM) cores that arise at the center of DM halos as they form. We show that such a DM formation channel can occur before star formation, leading to heavier BH seeds than standard baryonic channels. The SMBH seeds subsequently grow by accretion. We compute the evolution of the mass and angular momentum of the BH using a geodesic general relativistic disk accretion model. We show that these SMBH seeds grow to $\sim 10^9$-$10^{10} M_\odot$ in the first Gyr of the lifetime of the Universe without invoking unrealistic (or fine-tuned) accretion rates.

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C. Argüelles, K. Boshkayev, A. Krut, et. al.
Fri, 5 May 23
4/67

Comments: 11 pages, 9 figures, 2 appendices. Accepted for publication in MNRAS

http://arxiv.org/abs/2305.02863

The fluctuation of matter parameter $\sigma_8$ is by model construction degenerate with the growth index $\gamma$. Here we try to study the effect on the cosmological parameters constraints from treating each independently by considering $\sigma_8$ as a free and not derived parameter along with $\gamma$, to then try to constrain all by three probes, namely the CMB spectrum, the growth measurements from redshift space distortions $f\sigma_8$ and the galaxy cluster counts. We also want to asses the impact of this relaxation on the $\sigma_8$ tension. We also propose a more sophisticated correction, along with the classical one that takes into account the impact of cosmology on the growth measurements, which is to adjust the growth to keep the observed power spectrum invariant with the background evolution. We found that untying the two parameters does not shift the maximum likelihood on either $\sigma_8$ or $\gamma$ but rather allow for larger bounds with respect to when $\sigma_8$ is a derived parameter. More precisely, we obtain $\sigma_8 = 0.809\pm 0.043 $ and $\gamma = 0.613\pm 0.046$ in agreement with Planck constraints for the former and compatible with $\Lambda$CDM for the latter but with bounds enough wide to accomodate both values subject of tensions for $\sigma_8$. On the other hand, considering a tier correction yields $\sigma_8 = 0.734\pm 0.013$ close to the local values albeit with a growth index $\gamma = 0.636\pm 0.022$ while allowing a massive neutrinos yielded $\sigma_8 = 0.756\pm 0.024$, still preferring low values but with looser constraints, with $\gamma = 0.549\pm 0.048$ and a slight preference for $\Sigma m_\nu \sim 0.19$ value. We conclude that untying $\sigma_8$ and $\gamma$ helps in relieving the discomfort on the former between CMB and local probes and that careful analyse should be followed when using data obtained in a model dependent way.(abridged)

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Z. Sakr
Fri, 5 May 23
6/67

Comments: Prepared for a contribution to the special issue on Modified Gravity Approaches to the Tensions of {\Lambda}CDM

http://arxiv.org/abs/2305.02880

In this work, we study microlensing effects in strongly lensed gravitational wave (GW) signals corresponding to global minima in galaxy-scale lenses. We find that stellar microlenses alone are unable to introduce noticeable wave effects in the global minima GW signals at strong lensing magnification $(\mu)<50$ with match value between unlensed and lensed GW signals being above ${\sim}99.5\%$ in ${\sim}90\%$ of systems. Since the stellar microlenses introduce negligible wave effects in global minima, they can be used to probe the intermediate-mass black hole (IMBH) lenses in the galaxy lens. We show that the presence of an IMBH lens with mass in the range $[50,10^3]~{\rm M_\odot}$ such that the global minima lies within five Einstein radius of it, the microlensing effects at $f<10^2$ Hz are mainly determined by the IMBH lens for $\mu<50$. Assuming that a typical strong lensing magnification of 3.8 and high enough signal-to-noise ratio (in the range $\sim[10, 30]$) to detect the microlensing effect in GW signals corresponding to global minima, with non-detection of microlensing effects in ${\sim}15 ({\sim}150)$ lensed GW signals, we can rule out dark matter fraction $>10\% (>1\%)$ made of IMBH population inside galaxy lenses in mass range $[50, 10^3] {\rm M_\odot}$ with ${\sim}$90\% confidence.

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A. Meena
Fri, 5 May 23
13/67

Comments: 8 pages, 5 figures. Comments welcome

http://arxiv.org/abs/2305.02913

Models of dark energy or modified gravity that tries to alleviate the tensions on the Hubble constant ($H_0$) and the matter fluctuation parameter ($\sigma_8$) are usually parameterized as function of either late or early time cosmic evolution. In this work we rather focus on one that could privilege extensions to $\Lambda$CDM on intermediate redshifts by mean of a Gaussian-like window function with a free moving centre $a_{Gwin}$ combined with a modified gravity parameter $\mu_{Gwin}$ and an extension of the equation of state parameter $\omega_{Gwin}$. Using different combinations of the latest available current datasets subject of the discrepancies, such as the cosmic microwave (CMB) background power spectrum, the baryonic acoustic scale (BAO) in galaxy distribution, Weak lensing (WL) shear and galaxy clustering cross correlations and local hubble constant measurements, we investigate whether such model could alleviate each or both $H_0$ and $\sigma_8$ tensions. We found when combining all probes that the $\sigma_8$ tension is alleviated while the $H_0$ is reduced with a small preference for a positive $\omega_{Gwin}$ without a particular preference for a redshift or a $\mu_{Gwin}$ different from its equivalent $\Lambda$CDM value. However, if we follow another approach and compare the two sets of the probes subject of discrepancy i.e. CMB+BAO vs WL+local $H_0$, we found that the model is able of solving the $\sigma_8$ discrepancy at the expense of a enlargement of the constraints, while the Hubble constant discrepancy is not that affected due to the fact that the two likelihood contours are stretched in parallel directions. We conclude that modifying $\Lambda$CDM cosmology at intermediate redshifts within our model, and the constraints from the datasets used in this study, are not likely a viable solution to solve both tensions.

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Z. Sakr
Fri, 5 May 23
17/67

Comments: Prepared for proceedings of Corfu Summer Institute 2022 “School and Workshops on Elementary Particle Physics and Gravity”

http://arxiv.org/abs/2305.02846

We investigate whether the two cosmological discrepancies on the Hubble constant ($H_0$) and the matter fluctuation parameter ($\sigma_8$) could be traded by only one on the present value of the matter density ($\Omega_{\rm{M}}$). We combined different probes in an agnostic approach by, either relaxing the calibration parameters in each probe in order to be set by the data, or by only including priors with the condition that they are obtained independently from the discrepant parameters. We also compiled and used a dataset from previous direct measurements of $\Omega_{\rm{M}}$. We found when combining, as our baseline, galaxy clusters counts + cluster baryon fraction probe + cosmic chronometers + direct $\Omega_{\rm{M}}$ + priors from BBN and CMB, that both parameters, $H_0$ and $\sigma_8$, are consistent with those inferred with local probes, with $\sigma_8 = 0.745 \pm 0.05$ while $H_0 = 73.8 \pm 3.01$, and that for a value of $\Omega_{\rm{M}} = 0.22 \pm 0.01$ at more than 3$\sigma$ from that usually determined by CMB. We also found similar preferences when replacing cosmic chronometers (CC) by the Supernovae (SN) data while allowing its calibration parameter to vary. However discrepancies appeared when we combined SN in addition to CC suggesting either inconsistencies between the SN sample and the other probes used or a serious challenge to our hypothesis. We conclude that, either reconciling both tensions requires local inferred values of matter density at odd with those obtained by CMB, reviving by then an overlooked discrepancy, or simply that further evidences are indicating that $\Lambda$CDM model is facing more difficulties to accommodate simultaneously all the current available observations.(abridged)

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Z. Sakr
Fri, 5 May 23
33/67

Comments: Comments and missing citation requests are welcomed. Abstract abridged for arxiv submission