Tag Archives: Cosmology and Nongalactic Astrophysics

The comoving curvature perturbation in Jordan and Einstein frames [CL]

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http://arxiv.org/abs/2305.15326


In the context of $F(\phi)R$ models of gravity, the conformal invariance of the curvature perturbation on the uniform-field slicings has been already demonstrated in several publications. In this work, we study the conformal invariance of the curvature perturbation defined on hypersurfaces that are comoving with an effective fluid. We derive the comoving curvature perturbation in each conformal frame and relate both. It is shown that the conformal invariance of this gauge-invariant curvature perturbation does not always hold, and the analysis on superhorizon and subhorizon scales is performed in the slow-roll regime of inflation. We find that the comoving curvature perturbation is conformally invariant on superhorizon scales but the same cannot be concluded on the subhorizon regime.

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J. Díaz and M. Karčiauskas
Thu, 25 May 23
64/64

Comments: 21 pages

Distinguishing nanohertz gravitational wave sources through the observations of ultracompact minihalos [CEA]

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http://arxiv.org/abs/2305.15100


The common-spectrum process observed by pulsar-timing arrays is interpreted as stochastic gravitational wave backgrounds originating from various sources in the early Universe. Along with generating gravitational waves, we find energy density perturbations also arise with the sources such as bubble collisions and sound waves during first-order phase transitions, cosmic strings, domain walls, condensate fragmentation, and primordial curvature perturbations from inflation. These perturbations can lead to the formation of abundant ultracompact minihalos. Currently, the observational precision is inadequate for discriminating between different models. Then, ongoing and future astrophysical observations of ultracompact minihalos can help to distinguish and constrain the gravitational-wave sources in the nanohertz and $\mu$Hz bands.

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J. Liu
Thu, 25 May 23
64/64

Comments: 7 pages, 1 figure, 1 table

COOL-LAMPS. V. Discovery of COOL J0335$-$1927, a Gravitationally Lensed Quasar at $z$=3.27 with an Image Separation of 23.3" [GA]

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http://arxiv.org/abs/2305.14317


We report the discovery of COOL J0335$-$1927, a quasar at $z$ = 3.27 lensed into three images with a maximum separation of 23.3″ by a galaxy cluster at $z$ = 0.4178. We construct a parametric strong gravitational lens model using ground-based imaging, constrained by the redshift and positions of the quasar images as well as the positions of three other multiply-imaged background galaxies. Using our best-fit lens model, we calculate the predicted time delays between the three quasar images to be $\Delta$t${AB}=$ $241^{+41}{-12}$ and $\Delta$t${AC}=$ $-64^{+3}{-33}$ days. We also present g-band photometry from archival DECaLS imaging, and new multi-epoch observations obtained between September 18, 2022 UT and February 22, 2023 UT, which demonstrate significant variability in the quasar and which will eventually enable a measurement of the time delay between the three quasar images.

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K. Napier, M. Gladders, K. Sharon, et. al.
Wed, 24 May 23
81/81

Comments: 8 pages, 4 figures, 1 table

Methodological refinement of the submillimeter galaxy magnification bias. Paper III: cosmological analysis with tomography [CEA]

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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

Dark Sectors with Mass Thresholds Face Cosmological Datasets [CEA]

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http://arxiv.org/abs/2305.14166


Interacting dark sectors may undergo changes in the number of their relativistic species during the early universe, due to a mass threshold $m$ (similar to changes in the Standard Model bath), and in doing so affect the cosmic history. When such changes occur close to recombination, i.e., for $m\sim (0.1-10)~\text{eV}$, the stringent bound on the effective number of neutrino species, $N_{\text{eff}}$, can be relaxed and the value of the Hubble expansion rate $H_0$ inferred from Cosmic Microwave Background (CMB) observations raised. We search for such sectors (with and without mass thresholds) in the latest cosmological datasets, including the full-shape (FS) of BOSS DR12 galaxy power spectrum. We perform a detailed analysis, accounting for the choice of prior boundaries and additionally exploring the possible effects of dark sector interactions with (a fraction of) the dark matter. We find $\Delta N_{\text{eff}}\leq 0.55\, (0.46)$ at 95% C.L. with (without) a mass threshold. While a significantly larger Hubble rate is achieved in this scenario, $H_0=69.01^{+0.66}_{-1.1}$, the overall fit to CMB+FS data does not provide a compelling advantage over the $\Lambda$CDM model. Furthermore, we find that dark matter interactions with the dark sector do not significantly improve the (matter fluctuations) $S_8$ tension with respect to the $\Lambda$CDM model. Our work provides model-independent constraints on (decoupled) dark sectors with mass thresholds around the eV scale.

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I. Allali, F. Rompineve and M. Hertzberg
Wed, 24 May 23
81/81

Comments: 18 + 18 pages, 38 figures and tables

On the impact of the galaxy window function on cosmological parameter estimation [CEA]

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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

Clustering of Primordial Black Holes from QCD Axion Bubbles [CEA]

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http://arxiv.org/abs/2305.13023


We study the clustering of primordial black holes (PBHs) and axion miniclusters produced in the model proposed to explain the LIGO/Virgo events or the seeds of the supermassive black holes (SMBHs) in arXiv:2006.13137. It is found that this model predicts large isocurvature perturbations due to the clustering of PBHs and axion miniclusters, from which we obtain stringent constraints on the model parameters. Specifically, for the axion decay constant $f_a=10^{16}~\mathrm{GeV}$, which potentially accounts for the seeds of the SMBHs, the PBH fraction in dark matter should be $f_\mathrm{PBH}\lesssim7\times 10^{-10}$. Assuming that the mass of PBHs increases by more than a factor of $\mathcal{O}(10)$ due to accretion, this is consistent with the observed abundance of SMBHs. On the other hand, for $f_a=10^{17}~\mathrm{GeV}$ required to produce PBHs of masses detected in the LIGO/Virgo, the PBH fraction should be $f_\mathrm{PBH}\lesssim6\times 10^{-8}$, which may be too small to explain the LIGO/Virgo events, although there is a significant uncertainty in calculating the merger rate in the presence of clustering.

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K. Kasai, M. Kawasaki, N. Kitajima, et. al.
Tue, 23 May 23
77/77

Comments: 18 pages, 11 figures

Halo formation and evolution in SFDM and CDM: new insights from the fluid approach [GA]

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http://arxiv.org/abs/2305.12982


(abridged) We present simulations of halo formation and evolution in scalar field dark matter (SFDM) cosmologies in the Thomas-Fermi regime, aka SFDM-TF", where a strong repulsive 2-particle self-interaction (SI) is included, being a valuable alternative to CDM, with the potential to resolve itscusp-core” problem. In general, SFDM behaves like a quantum fluid. Previous literature has presented two fluid approximations for SFDM-TF, as well as simulations of halo formation. These results confirmed earlier expectations and are generally in mutual agreement, but discrepancies were also reported. Therefore, we perform dedicated 3D cosmological simulations for the SFDM-TF model, applying both fluid approximations, as well as for CDM. Our results are very well in accordance with previous works and extend upon them, in that we can explain the reported discrepancies as a result of different simulation setups. We find some interesting details: The evolution of both SFDM-TF and CDM halos follows a 2-stage process. In the early stage, the density profile in the center becomes close to a $(n=1.5)$-polytropic core, dominated by an “effective” velocity-dispersion pressure $P_{\sigma}$ which is common to both dark matter models. Consecutively, for CDM halos, the core transitions into a central cusp. In SFDM-TF halos, the additional pressure $P_\text{SI}$ due to SI determines the second stage of the evolution, where the central region follows closely a $(n=1)$-polytropic core, embedded in a nearly isothermal envelope, i.e. the outskirts are similar to CDM. We also encounter a new effect, namely a late-time expansion of both polytropic core plus envelope, because the size of the almost isothermal halo envelope is affected by the expansion of the background universe. So, an initial primordial core of $\sim 100$ pc can evolve into a larger core of $\gtrsim 1$ kpc, even without feedback from baryons.

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H. Foidl, T. Rindler-Daller and W. Zeilinger
Tue, 23 May 23
77/77

Comments: submitted to Phys.Rev.D; 26 pages, 16 figures

Revealing mass distributions of dwarf spheroidal galaxies in the Subaru-PFS era [GA]

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http://arxiv.org/abs/2305.11309


The Galactic dwarf spheroidal galaxies (dSphs) provide valuable insight into dark matter (DM) properties and its role in galaxy formation. Their close proximity enables the measurement of line-of-sight velocities for resolved stars, which allows us to study DM halo structure. However, uncertainties in DM mass profile determination persist due to the degeneracy between DM mass density and velocity dispersion tensor anisotropy. Overcoming this requires large kinematic samples and identification of foreground contamination. With 1.25 deg$^2$ and 2394 fibers, PFS plus pre-imaging with Hyper Suprime Cam will make significant progress in this undertaking.

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K. Hayashi, L. Dobos, C. Filion, et. al.
Mon, 22 May 23
1/60

Comments: 6 pages, 3 figures, Accepted for publication in Proceedings of the IAUS 379: Dynamical Masses of Local Group Galaxies, Potsdam, March 20-24, 2023

Coupled Multi Scalar Field Dark Energy [CEA]

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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

DarkAI: I. Mapping the large-scale density field of dark matter using AI [CEA]

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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

Evidence Networks: simple losses for fast, amortized, neural Bayesian model comparison [CL]

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http://arxiv.org/abs/2305.11241


Evidence Networks can enable Bayesian model comparison when state-of-the-art methods (e.g. nested sampling) fail and even when likelihoods or priors are intractable or unknown. Bayesian model comparison, i.e. the computation of Bayes factors or evidence ratios, can be cast as an optimization problem. Though the Bayesian interpretation of optimal classification is well-known, here we change perspective and present classes of loss functions that result in fast, amortized neural estimators that directly estimate convenient functions of the Bayes factor. This mitigates numerical inaccuracies associated with estimating individual model probabilities. We introduce the leaky parity-odd power (l-POP) transform, leading to the novel “l-POP-Exponential” loss function. We explore neural density estimation for data probability in different models, showing it to be less accurate and scalable than Evidence Networks. Multiple real-world and synthetic examples illustrate that Evidence Networks are explicitly independent of dimensionality of the parameter space and scale mildly with the complexity of the posterior probability density function. This simple yet powerful approach has broad implications for model inference tasks. As an application of Evidence Networks to real-world data we compute the Bayes factor for two models with gravitational lensing data of the Dark Energy Survey. We briefly discuss applications of our methods to other, related problems of model comparison and evaluation in implicit inference settings.

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N. Jeffrey and B. Wandelt
Mon, 22 May 23
12/60

Comments: 21 pages, 8 figures

Gravitational waves from walls bounded by strings in $SO(10)$ model of pseudo-Goldstone dark matter [CL]

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http://arxiv.org/abs/2305.11775


We explore the gravitational wave spectrum generated by string-wall structures in an $SO(10)$ ($Spin(10)$) based scenario of pseudo-Goldstone boson dark matter (pGDM) particle. This dark matter candidate is a linear combination of the Standard Model (SM) singlets present in the 126 and 16 dimensional Higgs fields. The Higgs $126$-plet vacuum expectation value (VEV) $\left<126_H\right>$ leaves unbroken the $\mathbb{Z}_2$ subgroup of $\mathbb{Z}_4$, the center of $SO(10)$. Among other things, this yields topologically stable cosmic strings with a string tension $\mu \sim \left<126_H\right>^2$. The subsequent (spontaneous) breaking of $\mathbb{Z}_2$ at a significantly lower scale by the $16$-plet VEV $\left<16_H\right>$ leads to the appearance of domain walls bounded by the strings produced earlier. We display the gravitational wave spectrum for $G \mu$ values varying between $10^{-15}$ and $10^{-9}$ ($\left<126_H\right>\sim 10^{11}$ – $10^{14}$ GeV), and $\left<16_H\right>\sim 0.1$ – $10^3$ TeV range ($G$ denotes Newton’s constant.) These predictions can be tested, as we show, by a variety of (proposed) experiments including LISA, ET, CE and others.

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R. Maji, W. Park and Q. Shafi
Mon, 22 May 23
22/60

Comments: 8 pages, 3 figures

Photo-zSNthesis: Converting Type Ia Supernova Lightcurves to Redshift Estimates via Deep Learning [CEA]

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http://arxiv.org/abs/2305.11869


Upcoming photometric surveys will discover tens of thousands of Type Ia supernovae (SNe Ia), vastly outpacing the capacity of our spectroscopic resources. In order to maximize the science return of these observations in the absence of spectroscopic information, we must accurately extract key parameters, such as SN redshifts, with photometric information alone. We present Photo-zSNthesis, a convolutional neural network-based method for predicting full redshift probability distributions from multi-band supernova lightcurves, tested on both simulated Sloan Digital Sky Survey (SDSS) and Vera C. Rubin Legacy Survey of Space and Time (LSST) data as well as observed SDSS SNe. We show major improvements over predictions from existing methods on both simulations and real observations as well as minimal redshift-dependent bias, which is a challenge due to selection effects, e.g. Malmquist bias. The PDFs produced by this method are well-constrained and will maximize the cosmological constraining power of photometric SNe Ia samples.

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H. Qu and M. Sako
Mon, 22 May 23
25/60

Comments: submitted to ApJ

Minimal Preheating [CL]

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http://arxiv.org/abs/2305.11246


An oscillating inflaton field induces small amplitude oscillations of the Hubble parameter at the end of inflation. These Hubble parameter induced oscillations, in turn, trigger parametric particle production of all light fields, even if they are not directly coupled to the inflaton. We here study the induced particle production for a light scalar field (e.g. the Standard Model Higgs field) after inflation as a consequence of this effect. Our analysis yields a model-independent lower bound on the efficiency of energy transfer from the inflaton condensate to particle excitations.

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R. Brandenberger, V. Kamali and R. Ramos
Mon, 22 May 23
30/60

Comments: 9 pages, 7 figures

Leading Loops in Cosmological Correlators [CL]

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http://arxiv.org/abs/2305.11228


Cosmological correlators from inflation are often generated at tree level and hence loop contributions are bounded to be small corrections by perturbativity. Here we discuss a scenario where this is not the case. Recently, it has been shown that for any number of scalar fields of any mass, the parity-odd trispectrum of a massless scalar must vanish in the limit of exact scale invariance due to unitarity and the choice of initial state. By carefully handling UV-divergences, we show that the one-loop contribution is non-vanishing and hence leading. Surprisingly, the one-loop parity-odd trispectrum is simply a rational function of kinematics, which we compute explicitly in a series of models, including single-clock inflation. Although the loop contribution is the leading term in the parity-odd sector, its signal-to-noise ratio is typically bounded from above by that of a corresponding tree-level parity-even trispectrum, unless instrumental noise and systematics for the two observables differ. Furthermore, we identify a series of loop contributions to the wavefunction that cancel exactly when computing correlators, suggesting a more general phenomenon.

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M. Lee, C. McCulloch and E. Pajer
Mon, 22 May 23
42/60

Comments: 34 pages, 4 figures

Azimuthal Anisotropy of Magnetic Fields in the Circumgalactic Medium Driven by Galactic Feedback Processes [GA]

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http://arxiv.org/abs/2305.11214


We use the TNG50 cosmological magnetohydrodynamical simulation of the IllustrisTNG project to show that magnetic fields in the circumgalactic medium (CGM) have significant angular structure. This azimuthal anisotropy at fixed distance is driven by galactic feedback processes that launch strong outflows into the halo, preferentially along the minor axes of galaxies. These feedback-driven outflows entrain strong magnetic fields from the interstellar medium, dragging fields originally amplified by small-scale dynamos into the CGM. At the virial radius, $z=0$ galaxies with M$\star \sim 10^{10}\,\rm{M\odot}$ show the strongest anisotropy ($\sim 0.35$ dex). This signal weakens with decreasing impact parameter, and is also present but weaker for lower mass as well as higher mass galaxies. Creating mock Faraday rotation measure (RM) sightlines through the simulated volume, we find that the angular RM trend is qualitatively consistent with recent observational measurements. We show that rich structure is present in the circumgalactic magnetic fields of galaxies. However, TNG50 predicts small RM amplitudes in the CGM that make detection difficult as a result of other contributions along the line of sight.

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R. Ramesh, D. Nelson, V. Heesen, et. al.
Mon, 22 May 23
47/60

Comments: Submitted to MNRAS. Comments welcome

A GPU-accelerated viewer for HEALPix maps [IMA]

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http://arxiv.org/abs/2305.11507


HEALPix by G\’orski et. al. (2005) is de-facto standard for Cosmic Microwave Background (CMB) data storage and analysis, and is widely used in current and upcoming CMB experiments. Almost all the datasets in Legacy Archive for Microwave Background Data Analysis (LAMBDA) use HEALPix as a format of choice. Visualizing the data plays important role in research, and several toolsets were developed to do that with HEALPix maps, most notably original Fortran facilities and Python integration with healpy.
With the current state of GPU performance, it is now possible to visualize extremely large maps in real time on a laptop or a tablet. HEALPix Viewer described here is developed for macOS, and takes full advantage of GPU acceleration to handle extremely large datasets in real time. It compiles natively on Intel and Arm64 architectures, and uses Metal framework for high-performance GPU computations. The aim of this project is to reduce the effort required for interactive data exploration, as well as time overhead for producing publication-quality maps. Drag and drop integration with Keynote and Powerpoint makes creating presentations easy.
The main codebase is written in Swift, a modern and efficient compiled language, with high-performance computing parts delegated entirely to GPU, and a few inserts in C interfacing to cfitsio library for I/O. Graphical user interface is written in SwiftUI, a new declarative UI framework based on Swift. Most common spherical projections and colormaps are supported out of the box, and the available source code makes it easy to customize the application and to add new features if desired.

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A. Frolov
Mon, 22 May 23
52/60

Comments: 10 pages; 7 figures

Two-Screen Scattering in CRAFT FRBs [HEAP]

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http://arxiv.org/abs/2305.11477


Temporal broadening is a commonly observed property of fast radio bursts (FRBs), associated with turbulent media which cause radiowave scattering. Similarly to dispersion, scattering is an important probe of the media along the line of sight to an FRB source, such as the circum-burst or circum-galactic mediums (CGM). Measurements of characteristic scattering times alone are insufficient to constrain the position of the dominant scattering media along the line of sight. However, where more than one scattering screen exists, Galactic scintillation can be leveraged to form strong constraints. We quantify the scattering and scintillation in 10 FRBs with 1) known host galaxies and redshifts and 2) captured voltage data enabling high time resolution analysis, obtained from the Commensal Real-time ASKAP (Australian Square Kilometre Array Pathfinder) Fast Transient survey science project (CRAFT). We find strong evidence for two screens in three cases. For FRBs 20190608B and 20210320C, we find evidence for scattering screens less than approximately 16.7 and 3000 kpc respectively, from their sources. For FRB 20201124A we find evidence for a scattering screen at $\approx$26 kpc. Each of these measures is consistent with the scattering occurring in the host ISM (inter-stellar medium) or CGM. If pulse broadening is assumed to be contributed by the host galaxy ISM or circum-burst environment, the definitive lack of observed scintillation in four FRBs in our sample suggests that existing models may be over-estimating scattering times associated with the Milky Way’s ISM, similar to the anomalously low scattering observed for FRB 20201124A.

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M. Sammons, A. Deller, M. Glowacki, et. al.
Mon, 22 May 23
53/60

Comments: 13 pages, 9 figures, 1 table. Submitted to MNRAS

A large $|η|$ approach to single field inflation [CL]

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http://arxiv.org/abs/2305.11568


Single field models of inflation capable to produce primordial black holes usually require a significant departure from the standard, perturbative slow-roll regime. In fact, in many of these scenarios, the size of the slow-roll parameter $|\eta|$ becomes larger than one during a short phase of inflationary evolution. In order to develop an analytical control on these systems, we explore the limit of $|\eta|$ large, and promote $1/|\eta|$ to a small quantity to be used for perturbative expansions. Formulas simplify, and we obtain analytic expressions for the two and three point functions of curvature fluctuations, which share some of the features found in realistic inflationary models generating primordial black holes. We study one-loop corrections in this framework: we discuss criteria for adsorbing ultraviolet divergences into the available parameters, leaving log-enhanced infrared contributions of controllable size.

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G. Tasinato
Mon, 22 May 23
54/60

Comments: 20 pages, 3 figures

EDGES and JWST with 21cm global signal emulator [CEA]

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http://arxiv.org/abs/2305.11441


The 21cm global signal is an important probe to reveal the properties of the first astrophysical objects and the processes of the structure formation from which one can constrain astrophysical and cosmological parameters. To extract the information of such parameters, one needs to efficiently evaluate the 21cm global signal for statistical analysis. First we developed an artificial neural network-based emulator to predict the 21cm global signal, which works with significantly less computational cost and high precision. Then we apply our emulator to demonstrate the parameter estimation based on the Bayesian analysis by using the publicly available EDGES low-band data. We find that the result is sensitive to the foreground model, the assumption of noise, and the frequency range used in the analysis. The Bayesian evidence suggests the models with higher order polynomial function and enhanced noise are preferred. We also compare models suggested from the EDGES low-band data and the ones from recent JWST measurements of the galaxy luminosity function at $z=16$. We find that the model which produces the 21cm absorption line at $z\approx15$ is well consistent with the central value of the observed luminosity function at $z=16$.

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S. Yoshiura, T. Minoda and T. Takahashi
Mon, 22 May 23
56/60

Comments: 11 pages, 12 figures, 3 tables. Comments welcome

Cosmic string bursts in LISA [CL]

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http://arxiv.org/abs/2305.11653


Cosmic string cusps are sources of short-lived, linearly polarised gravitational wave bursts which can be searched for in gravitational wave detectors. We assess the capability of LISA to detect these bursts using the latest LISA configuration and operational assumptions. For such short bursts, we verify that LISA can be considered as “frozen”, namely that one can neglect LISA’s orbital motion. We consider two models for the network of cosmic string loops, and estimate that LISA should be able to detect 1-3 bursts per year assuming a string tension $G\mu \approx 10^{-11} – 10^{-10.5}$ and detection threshold $\rm{SNR} \ge 20$. Non-detection of these bursts would constrain the string tension to $G\mu\lesssim 10^{-11}$ for both models.

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P. Auclair, S. Babak, H. Leclere, et. al.
Mon, 22 May 23
60/60

Comments: 6 pages

A novel approach to infer population and cosmological properties with gravitational waves standard sirens and galaxy surveys [CEA]

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http://arxiv.org/abs/2305.10488


Gravitational wave (GW) sources at cosmological distances can be used to probe the expansion rate of the Universe. GWs directly provide a distance estimation of the source but no direct information on its redshift. The optimal scenario to obtain a redshift is through the direct identification of an electromagnetic (EM) counterpart and its host galaxy. With almost 100 GW sources detected without EM counterparts (dark sirens), it is becoming crucial to have statistical techniques able to perform cosmological studies in the absence of EM emission. Currently, only two techniques for dark sirens are used on GW observations: the spectral siren method, which is based on the source-frame mass distribution to estimate conjointly cosmology and the source’s merger rate, and the galaxy survey method, which uses galaxy surveys to assign a probabilistic redshift to the source while fitting cosmology. It has been recognized, however, that these two methods are two sides of the same coin. In this paper, we present a novel approach to unify these two methods. We apply this approach to several observed GW events using the \textsc{glade+} galaxy catalog discussing limiting cases. We provide estimates of the Hubble constant, modified gravity propagation effects, and population properties for binary black holes. We also estimate the binary black hole merger rate per galaxy to be $10^{-6}-10^{-5} {\rm yr^{-1}}$ depending on the galaxy catalog hypotheses.

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S. Mastrogiovanni, D. Laghi, R. Gray, et. al.
Fri, 19 May 23
1/46

Comments: 16 pages, 9 figures

Primordial black holes from null energy condition violation during inflation [CL]

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http://arxiv.org/abs/2305.10933


The violation of the null energy condition (NEC) is closely related to potential solutions for the cosmological singularity problem and may therefore play a crucial role in the very early universe. We explore a novel approach to generate primordial black holes (PBHs) via the violation of the NEC in a single-field inflationary scenario. In our scenario, the universe transitions from a first slow-roll inflation stage with a Hubble parameter H = Hinf1 to a second slow-roll inflation stage with H = Hinf2 > Hinf1, passing through an intermediate stage of NEC violation. The resulting primordial scalar power spectrum is naturally enhanced by the NEC violation at a certain wavelength. As a result, PBHs with masses and abundances of observational interest can be produced in our scenario. We also examine the phenomenological signatures of scalar-induced gravitational waves (SIGWs). Our work highlights the significance of utilizing a combination of PBHs, SIGWs, and primordial gravitational waves as a powerful probe for exploring the NEC violation during inflation.

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Y. Cai, M. Zhu and Y. Piao
Fri, 19 May 23
5/46

Comments: 8 pages, 5 figures

Cogenesis of matter and dark matter from triplet fermion seesaw [CL]

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http://arxiv.org/abs/2305.11138


We propose a simple model in the type-III seesaw framework to explain the recently reported W-mass anomaly by CDF-II collaboration, neutrino mass, asymmetric dark matter, and baryon asymmetry of the Universe. We extend the standard model with a vector-like singlet lepton ($\chi$) and a hypercharge zero scalar triplet ($\Delta$) in addition to three hypercharge zero triplet fermions($\Sigma_i~,i=1,2,3$). A $Z_2$ symmetry is imposed under which $\chi$ and $\Delta$ are odd, while all other particles are even. As a result, the lightest $Z_2$ odd particle $\chi$ behaves as a candidate of dark matter. In the early Universe, the CP-violating out-of-equilibrium decay of heavy triplet fermions to the Standard Model lepton ($L$) and Higgs ($H$) generate a net lepton asymmetry, while that of triplet fermions to $\chi$ and $\Delta$ generate a net asymmetric dark matter. The lepton asymmetry is converted to the required baryon asymmetry of the Universe via the electroweak sphalerons, while the asymmetry in $\chi$ remains as a dark matter relic that we observe today. We introduce a singlet scalar $\phi$, with mass $m_\phi < m_\chi$, which not only assists to deplete the symmetric component of $\chi$ through the annihilation process: $\bar{\chi} \chi \to \phi \phi$ but also paves a path to detect dark matter $\chi$ at direct search experiments through $\phi-H$ mixing. The $Z_2$ symmetry is broken softly resulting in an unstable asymmetric dark matter with mass ranging from a few MeV to a few tens of GeV. The softly broken $Z_2$ symmetry also induces a vacuum expectation value (vev) of $\Delta$ due to which the asymmetry in $\Delta$ disappears. Moreover, the vev of $\Delta$ enhances the W-boson mass as reported by CDF-II collaboration with $7\sigma$ statistical significance, while keeping the $Z$-boson mass intact.

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S. Mahapatra, P. Paul, N. Sahu, et. al.
Fri, 19 May 23
8/46

Comments: 33 pages, 19 captioned figures

Precise self-calibration of interloper bias in spectroscopic surveys [CEA]

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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

Quijote-PNG: The Information Content of the Halo Mass Function [CEA]

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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

The warm inflation story [CL]

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http://arxiv.org/abs/2305.10879


Warm inflation has normalized two ideas in cosmology, that in the early universe the initial primordial density perturbations generally could be of classical rather than quantum origin and that during inflation, particle production from interactions amongst quantum field, and its backreaction effects, can occur concurrent with inflationary expansion. When we first introduced these ideas, both were met with resistance, but today they are widely accepted as possibilities with many models and applications based on them, which is an indication of the widespread influence of warm inflation. Open quantum field theory, which has been utilized in studies of warm inflation, is by now a relevant subject in cosmology, in part due to this early work. In this review I first discuss the basic warm inflation dynamics. I then outline how to compute warm inflation dynamics from first principles quantum field theory (QFT) and in particular how a dissipative term arises. Warm inflation models can have an inflaton mass bigger than the Hubble scale and the inflaton field excursion can remain sub-Planckian, thus overcoming the most prohibitive problems of inflation model building. I discuss the early period of my work in developing warm inflation that helped me arrive at these important features of its dynamics. Inflationary cosmology today is immersed in hypothetical models, which by now are acting as a diversion from reaching any endgame in this field. I discuss better ways to approach model selection and give necessary requirements for a well constrained and predictive inflation model. I point out a few warm inflation models that could be developed to this extent. I discuss how at this stage more progress would be made in this subject by taking a broader view on the possible early universe solutions that include not just inflation but the diverse range of options.

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A. Berera
Fri, 19 May 23
23/46

Comments: N/A

Relativistic drag forces on black holes from scalar dark matter clouds of all sizes [CL]

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http://arxiv.org/abs/2305.10492


We use numerical simulations of scalar field dark matter evolving on a moving black hole background to confirm the regime of validity of (semi-)analytic expressions derived from first principles for both dynamical friction and momentum accretion in the relativistic regime. We cover both small and large clouds (relative to the de Broglie wavelength of the scalars), and light and heavy particle masses (relative to the BH size). In the case of a small dark matter cloud, the effect of accretion is a non-negligible contribution to the total force on the black hole, even for small scalar masses. We confirm that this momentum accretion transitions between two regimes (wave- and particle-like) and we identify the mass of the scalar at which the transition between regimes occurs.

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D. Traykova, R. Vicente, K. Clough, et. al.
Fri, 19 May 23
27/46

Comments: 11 pages, 5 figures. Comments welcome!

Parameterized Parity Violation in Gravitational Wave Propagation [CL]

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http://arxiv.org/abs/2305.10478


Gravitational parity violation arises in a variety of theories beyond general relativity. Gravitational waves in such theories have their propagation altered, leading to birefringence effects in both the amplitude and speed of the wave. In this work, we introduce a generalized, theory-motivated parametrization scheme to study parity violation in gravitational wave propagation. This parametrization maps to parity-violating gravity theories in a straightforward way. We find that the amplitude and velocity birefringence effects scale with an effective distance measure that depends on how the dispersion relation is modified. Furthermore, we show that this generic parametrization can be mapped to the parametrized-post-Einsteinian (ppE) formalism with convenient applications to gravitational wave observations and model-agnostic tests of general relativity. We derive a mapping to the standard ppE waveform of the gravitational wave response function, and also find a ppE waveform mapping at the level of the polarization modes, $h_+$ and $h_\times$. Finally, we show how existing constraints in the literature translate to bounds on our new parity-violating parameters and discuss avenues for future analysis.

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L. Jenks, L. Choi, M. Lagos, et. al.
Fri, 19 May 23
31/46

Comments: 19 pages

Primordial Black Hole Reheating [CL]

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http://arxiv.org/abs/2305.10518


Post-inflationary reheating phase is usually said to be solely governed by the decay of coherently oscillating inflaton into radiation. In this submission, we explore a new avenue toward reheating through the evaporation of primordial black holes (PBHs). After the inflation, if PBHs form, depending on its initial mass, abundance, and inflaton coupling with the radiation, we found two physically distinct possibilities of reheating the universe. In one possibility, the thermal bath is solely obtained from the decay of PBHs while inflaton plays the role of dominant energy component in the entire process. In the other possibility, we found that PBHs itself dominate the total energy budget of the Universe during the course of evolution, and then its subsequent evaporation leads to radiation dominated universe. Furthermore, we analyze the impact of both monochromatic and extended PBH mass functions and estimate the detailed parameter ranges for which those distinct reheating histories are realized.

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M. Haque, E. Kpatcha, D. Maity, et. al.
Fri, 19 May 23
44/46

Comments: 17 pages, 9 figures

SP(k) — A hydrodynamical simulation-based model for the impact of baryon physics on the non-linear matter power spectrum [CEA]

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http://arxiv.org/abs/2305.09710


Upcoming large-scale structure surveys will measure the matter power spectrum to approximately percent level accuracy with the aim of searching for evidence for new physics beyond the standard model of cosmology. In order to avoid biasing our conclusions, the theoretical predictions need to be at least as accurate as the measurements for a given choice of cosmological parameters. However, recent theoretical work has shown that complex physical processes associated with galaxy formation (particularly energetic feedback processes associated with stars and especially supermassive black holes) can alter the predictions by many times larger than the required accuracy. Here we present $\texttt{SP(k)}$, a model for the effects of baryon physics on the non-linear matter power spectrum based on a new large suite of hydrodynamical simulations. Specifically, the ANTILLES suite consists of 400 simulations spanning a very wide range of the “feedback landscape” and show that the effects of baryons on the matter power spectrum can be understood at approaching the percent level in terms of the mean baryon fraction of haloes, at scales of up to $k \lesssim 10 \, h \, $Mpc$^{-1}$ and redshifts up to $z=3$. For the range of scales and redshifts that will be probed by forthcoming cosmic shear measurements, most of the effects are driven by galaxy group-mass haloes ($M \sim 10^{13-14}$ M$_\odot$). We present a simple Python implementation of our model, available at $\href{https://github.com/jemme07/pyspk}{\mathrm{https{:}//github.com/jemme07/pyspk}}$, which can be used to incorporate baryon effects in standard gravity-only predictions, allowing for marginalisation over baryon physics within cosmological pipelines.

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J. Salcido, I. McCarthy, J. Kwan, et. al.
Thu, 18 May 23
2/67

Comments: Refereed version accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS). 16 pages, 11 figures

A non-linear solution to the $S_8$ tension II: Analysis of DES Year 3 cosmic shear [CEA]

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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

The HI intensity mapping power spectrum: insights from recent measurements [CEA]

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http://arxiv.org/abs/2305.09720


The first direct measurements of the HI intensity mapping power spectrum were recently made using the MeerKAT telescope. These measurements are on nonlinear scales, at redshifts 0.32 and 0.44. We develop a formalism for modelling small-scale power in redshift space, within the context of the mass-weighted HI halo model framework. This model is consistent with the latest findings from surveys on the HI-halo mass relation. In order to model nonlinear scales, we include the 1-halo, shot-noise and finger-of-god effects. Then we apply the model to the MeerKAT auto-correlation data, finding that the model provides a good fit to the data at redshift 0.32, but the data may indicate some evidence for an adjustment at $z \sim 0.44$. Such an adjustment can be achieved by an increase in the HI halo model bias.

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H. Padmanabhan, R. Maartens, O. Umeh, et. al.
Thu, 18 May 23
7/67

Comments: 7 pages, 5 figures

Performance of the Quasar Spectral Templates for the Dark Energy Spectroscopic Instrument [IMA]

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http://arxiv.org/abs/2305.10426


Millions of quasar spectra will be collected by the Dark Energy Spectroscopic Instrument (DESI), leading to a four-fold increase in the number of known quasars. High accuracy quasar classification is essential to tighten constraints on cosmological parameters measured at the highest redshifts DESI observes ($z>2.0$). We present the spectral templates for identification and redshift estimation of quasars in the DESI Year 1 data release. The quasar templates are comprised of two quasar eigenspectra sets, trained on spectra from the Sloan Digital Sky Survey. The sets are specialized to reconstruct quasar spectral variation observed over separate yet overlapping redshift ranges and, together, are capable of identifying DESI quasars from $0.05 < z <7.0$. The new quasar templates show significant improvement over the previous DESI quasar templates regarding catastrophic failure rates, redshift precision and accuracy, quasar completeness, and the contamination fraction in the final quasar sample.

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A. Brodzeller, K. Dawson, S. Bailey, et. al.
Thu, 18 May 23
9/67

Comments: submitted to Astronomical Journal; 20 pages, 6 figures

Aspherical ULDM Collapse: Variation in the Core-Halo Mass Relation [CEA]

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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

An optimized search for dark matter in the galactic halo with HAWC [HEAP]

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http://arxiv.org/abs/2305.09861


The Galactic Halo is a key target for indirect dark matter detection. The High Altitude Water Cherenkov (HAWC) observatory is a high-energy (~300 GeV to >100 TeV) gamma-ray detector located in central Mexico. HAWC operates via the water Cherenkov technique and has both a wide field of view of 2 sr and a >95% duty cycle, making it ideal for analyses of highly extended sources. We made use of these properties of HAWC and a new background-estimation technique optimized for extended sources to probe a large region of the Galactic Halo for dark matter signals. With this approach, we set improved constraints on dark matter annihilation and decay between masses of 10 and 100 TeV. Due to the large spatial extent of the HAWC field of view, these constraints are robust against uncertainties in the Galactic dark matter spatial profile.

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A. Albert, R. Alfaro, C. Alvarez, et. al.
Thu, 18 May 23
20/67

Comments: 19 pages, 14 figures

Field-level Lyman-alpha forest modelling in redshift space via augmented non-local Fluctuating Gunn-Peterson Approximation [CEA]

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http://arxiv.org/abs/2305.10428


We present an improved analytical model to predict the Lyman-alpha forest at the field level in redshift space from the dark matter field, expanding upon the widely-used Fluctuating Gunn-Peterson approximation (FGPA). In particular, we introduce the dependence on the cosmic web environment (knots, filaments, sheets, voids) in the model, thereby effectively accounting for non-local bias. Furthermore, we include a detailed treatment of velocity bias in the redshift space distortions modelling, allowing the velocity bias to be cosmic-web dependent. We find evidence for a significant difference of the same model parameters in different environments, suggesting that for the investigated setup the simple standard FGPA is not able to adequately predict the Lyman-alpha forest in the different cosmic web regimes. We reproduce the summary statistics of the reference cosmological hydrodynamic simulation we use for comparison, yielding accurate mean transmitted flux, probability distribution function, 3D power spectrum, and bispectrum. In particular, we achieve maximum deviation and average deviations accuracy in the Lyman-alpha forest 3D power spectrum of $\sim 3\%$ and $\sim 0.1\%$ up to $k\sim 0.4 \, h \, {\rm Mpc}^{-1}$, $\sim 5\%$ and $\sim 1.8\%$ up to $k \sim 1.4 \, h \, {\rm Mpc}^{-1}$. Our new model outperforms previous analytical efforts to predict the Lyman-alpha forest at the field level in all the probed summary statistics, and has the potential to become instrumental in the generation of fast accurate mocks for covariance matrices estimation in the context of current and forthcoming Lyman-alpha forest surveys.

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F. Sinigaglia, F. Kitaura, K. Nagamine, et. al.
Thu, 18 May 23
24/67

Comments: 13 pages, 4 figures, 2 tables. Submitted to A&A. Comments welcome

SRF Cavity Searches for Dark Photon Dark Matter: First Scan Results [CL]

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http://arxiv.org/abs/2305.09711


We present the first use of a tunable superconducting radio frequency cavity to perform a scan search for dark photon dark matter with novel data analysis strategies. We mechanically tuned the resonant frequency of a cavity embedded in the liquid helium with a temperature of $2$ K, scanning the dark photon mass over a frequency range of $1.37$ MHz centered at $1.3$ GHz. By exploiting the superconducting radio frequency cavity’s considerably high quality factors of approximately $10^{10}$, our results demonstrate the most stringent constraints to date on a substantial portion of the exclusion parameter space, particularly concerning the kinetic mixing coefficient between dark photons and electromagnetic photons $\epsilon$, yielding a value of $\epsilon < 2.2 \times 10^{-16}$.

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Z. Tang, B. Wang, Y. Chen, et. al.
Thu, 18 May 23
29/67

Comments: 11 pages, 7 figures

On the redshift evolution of the baryon and gas fraction in simulated groups and clusters of galaxies [CEA]

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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

Gravitational Positivity for Phenomenologists: Dark Gauge Boson in the Swampland [CL]

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http://arxiv.org/abs/2305.10058


The gravitational positivity bound gives quantitative “swampland” constraints on low-energy effective theories inside theories of quantum gravity. We give a comprehensive discussion of this bound for those interested in applications to phenomenological model building. We present a practical recipe for deriving the bound, and discuss subtleties relevant for realistic models. As an illustration, we study the positivity bound on the scattering of the massive gauge bosons in the Higgs/St\”{u}ckelberg mechanism. Under certain assumptions on gravitational amplitudes at high energy, we obtain a lower bound $m_{V} \gtrsim \Lambda_\mathrm{UV}^2 /g M_\mathrm{Pl}$ on the gauge boson mass $m_V$, where $g$ is the coupling constant of the gauge field, $M_\mathrm{Pl}$ is the reduced Planck mass and $\Lambda_\mathrm{UV}$ is the ultraviolet cutoff of the effective field theory. This bound can strongly constrain new physics models involving a massive gauge boson.

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K. Aoki, T. Noumi, R. Saito, et. al.
Thu, 18 May 23
38/67

Comments: 30 pages, 12 figures

WIMP decay as a possible Warm Dark Matter model [CEA]

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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

Reducing the uncertainty on the Hubble constant up to 35\% with an improved statistical analysis: different best-fit likelihoods for Supernovae Ia, Baryon Acoustic Oscillations, Quasars, and Gamma-Ray Bursts [CEA]

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http://arxiv.org/abs/2305.10030


Cosmological models and their parameters are widely debated, especially about whether the current discrepancy between the values of the Hubble constant, $H_{0}$, obtained by type Ia supernovae (SNe Ia), and the Planck data from the Cosmic Microwave Background Radiation could be alleviated when alternative cosmological models are considered. Thus, combining high-redshift probes, such as Gamma-Ray Bursts (GRBs) and Quasars (QSOs), together with Baryon Acoustic Oscillations (BAO) and SNe Ia is important to assess the viability of these alternative models and if they can cast further light on the Hubble tension. In this work, for GRBs, we use a 3-dimensional relation between the peak prompt luminosity, the rest-frame time at the end of the X-ray plateau, and its corresponding luminosity in X-rays: the 3D Dainotti fundamental plane relation. Regarding QSOs, we use the Risaliti-Lusso relation among the UV and X-ray luminosities for a sample of 2421 sources. We correct both the QSO and GRB relations by accounting for selection and evolutionary effects with a reliable statistical method. We here use both the traditional Gaussian likelihoods ($\cal L_G$) and the new best-fit likelihoods ($\cal L_N$) to infer cosmological parameters of a non-flat $\Lambda$CDM and flat $w$CDM models. We obtain for all the parameters reduced uncertainties, up to $35\%$ for $H_{0}$, when applying the new $\cal L_N$ likelihoods in place of the Gaussian ones. Our results remain consistent with a flat $\Lambda$CDM model, although with a shift of the dark energy parameter $w$ toward $w<-1$ and a curvature density parameter toward $\Omega_k<0$.

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M. Dainotti, G. Bargiacchi, M. Bogdan, et. al.
Thu, 18 May 23
44/67

Comments: Accepted for publication at ApJ

The signature of galaxy formation models in the power spectrum of the hydrogen 21cm line during reionization [GA]

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http://arxiv.org/abs/2305.09721


Observations of the 21cm line of neutral hydrogen are poised to revolutionize our knowledge of cosmic reionization and the high-redshift population of galaxies. However, harnessing such information requires robust and comprehensive theoretical modeling. We study the non-linear effects of hydrodynamics and astrophysical feedback processes, including stellar and AGN feedback, on the 21cm signal by post-processing three existing cosmological hydrodynamical simulations of galaxy formation: Illustris, IllustrisTNG, and Eagle. Overall and despite their different underlying galaxy-formation models, the three simulations return similar predictions for the global 21cm rightness temperature and its power spectrum. At fixed redshift, most differences are attributable to differences in the history of reionization, in turn driven by differences in the build-up of stellar sources of radiation. However, the impact of astrophysics is imprinted in the 21cm power spectrum through several unique signatures. First, we find significant small scale ($k \geq 10\, \rm {Mpc}^{-1}$) differences between Illustris and IllustrisTNG, where higher velocity winds generated by supernova feedback soften density peaks and lead to lower 21cm power in TNG. Second, we find more 21cm power at intermediate scales ($k \approx 0.8\, \rm {Mpc}^{-1}$) in Eagle, due to differences in ionization driven by highly effective stellar feedback, leading to lower star formation, older and redder stellar populations, and thus lower ionizing luminosities. Though subtle, these features could allow future observations of the 21cm signal, in conjunction with other reionization observables, to constrain theoretical models for galactic feedback at high redshift.

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J. Lewis, A. Pillepich, D. Nelson, et. al.
Thu, 18 May 23
47/67

Comments: submitted to MNRAS (12/05/23)

An improved Compton parameter map of thermal Sunyaev-Zeldovich effect from Planck PR4 data [CEA]

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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

Constraints on the spectral signatures of superconducting cosmic strings [CEA]

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http://arxiv.org/abs/2305.09816


If they exist, networks of superconducting cosmic strings are capable of injecting copious amounts of electromagnetic energy into the background over a broad range of frequencies. We study this injection both analytically, as well as numerically using the thermalization code CosmoTherm. With our refined analytic formalism, we update constraints from CMB spectral distortions by following the injection of entropy, as well as energy, on the amplitude of the $\mu$-distortion, leading to a significant improvement in those limits. Furthermore, we utilize the full shape of the distorted spectrum from CosmoTherm to include constraints from non-$\mu$, non-$y$ type distortions. Additionally, we use the outputs for the ionization history and global 21cm signal to derive and update constraints on string model parameters using measurements from other datasets. Analysis of CMB anisotropies provides the most stringent constraints, though with a slightly modified shape and strength when compared to previous results. Modifications of the reionization history provide new bounds in the high current domain, and we also find that the observations of the low-frequency radio background probe a small region of parameter space not explored by other datasets. We also analyze global $21$-cm constraints, and find that the inclusion of soft photon heating plays a crucial role, essentially removing any constraints in the considered parameter domain. Spectral distortion measurements from COBE/FIRAS are covered by other constraints, but our conservative forecast shows that a PIXIE-type satellite would probe important unexplored regions of parameter space.

Read this paper on arXiv…

B. Cyr, J. Chluba and S. Acharya
Thu, 18 May 23
55/67

Comments: 21 pages, 24 figures, comments welcome!

Measuring $μ$-Distortions from the Thermal Sunyaev-Zeldovich effect [CEA]

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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.

Read this paper on arXiv…

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

Comments: 15 pages, 5 figures

The Tiered Radio Extragalactic Continuum (T-RECS) simulation II: HI emission and continuum-HI cross-correlation [GA]

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http://arxiv.org/abs/2305.10175


In this paper we extend the Tiered Radio Extragalactic Continuum Simulation (T-RECS) to include HI emission. The HI T-RECS model is based on the most recent HI mass function estimates, combined with prescriptions to convert HI mass to total integrated HI flux. It further models source size, morphology and kinematics, including rotational velocity and HI line width. The continuum T-RECS model is updated to improve the agreement with deeper number counts available at 150\,MHz. The model for star-forming galaxies (SFGs) is also modified according to the most recent indications of a star formation rate (SFR)–radio luminosity relation, which depends primarily on stellar mass rather than redshift. We further introduce prescriptions to associate an HI mass to the T-RECS radio continuum SFG and Active Galactic Nuclei (AGN) populations. This gives us a way to meaningfully associate counterparts between HI and continuum catalogues, thus building HI $\times$ continuum simulated observations. Clustering properties of the sources in both HI and continuum are reproduced by associating the galaxies to dark matter haloes of a cosmological simulation. We deliver a set of mock catalogues, as well as the code to produce them, which can be used for simulating observations and predicting results from radio surveys with existing and forthcoming radio facilities, such as the Square Kilometre Array (SKA)

Read this paper on arXiv…

A. Bonaldi, P. Hartley, T. Ronconi, et. al.
Thu, 18 May 23
57/67

Comments: 18 pages, 10 figures

Cluster-counterpart Voids: Void Identification from Galaxy Density Field [CEA]

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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

Constraining the redshift of BL Lac VER J0521+211 [HEAP]

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http://arxiv.org/abs/2305.09935


Observation of several very high energy (VHE) flaring events of the BL Lac object VER J0521+211 were reported by the VERITAS and MAGIC collaborations between 2009 and 2014. The redshift of this source is uncertain and several analysis have derived different limits for it. In the framework of the photohadronic model, and using three different extragalactic background light (EBL) models, we analyze seven independent VHE spectra of VER J0521+211 and determine the limiting values on its redshift. It is observed that the photohadronic scenario provides excellent fits to the reported observations. It is further observed that the photohadronic scenario, along with the EBL model of Dominguez et al., puts the most restrictive limits on the redshift z of VER J0521+211: 0.29 <= z <= 0.31 from the confidence level (CL) intervals at 2 sigma, or a more conservative 0.28 <= z <= 0.33, at 3 sigma.

Read this paper on arXiv…

S. Sahu, B. Medina-Carrillo, G. Sánchez-Colón, et. al.
Thu, 18 May 23
63/67

Comments: 9 pages, two columns, 2 figures, 6 figures in Appendix, accepted in MNRAS

Evolution of Cosmological Parameters and Fundamental Constants in a Flat Quintessence Cosmology: A Dynamical Alternative to ΛCDM [CEA]

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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

Unimodular Proca Theory: Breaking the U(1) gauge symmetry of unimodular gravity via a mass term [CL]

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http://arxiv.org/abs/2305.09380


We study the Hamiltonian structure of unimodular-like theories, where the cosmological constant (or other supposed constants of nature) are demoted from fixed parameters to classical constants of motion. No new local degrees of freedom are present as a result of a $U(1)$ gauge invariance of the theory. Hamiltonian analysis of the action reveals that the only possible gauge fixing that can be enforced is setting the spatial components of the four-volume time vector ${\cal T}^{i}\approx0$. As a consequence of this, the gauge-fixed unimodular path integral is equivalent to the minisuperspace unimodular path integral. However, should we break the $U(1)$ gauge invariance, two things happen: a massless propagating degree of freedom appears, and the (gauge-invariant) zero-mode receives modified dynamics. The implications are investigated, with the phenomenology depending crucially on the target “constant”.

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R. Isichei and J. Magueijo
Wed, 17 May 23
11/67

Comments: N/A

Consistent clustering and lensing of SDSS-III BOSS galaxies with an extended abundance matching formalism [CEA]

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http://arxiv.org/abs/2305.09637


Several analyses have shown that LCDM-based models cannot jointly describe the clustering (GC) and galaxy-galaxy lensing (GGL) of galaxies in the SDSS-III BOSS survey, which is commonly known as the ‘lensing-is-low problem’. In this work, we show that an extension of Subhalo Abundance Matching, dubbed SHAMe, successfully solves this problem. First, we show that this model accurately reproduces the GC and GGL of a mock galaxy sample in the TNG300 hydrodynamic simulation with analogous properties to BOSS galaxies. Then, we switch our attention to observed BOSS galaxies at z=0.31-0.43, and we attempt to reproduce their GC and GGL by evaluating SHAMe on two different simulations: one adopting best-fitting cosmological parameters from Planck and the other from weak gravitational lensing surveys (Low S8), where the amplitude of matter fluctuations is lower for the latter. We find excellent agreement between SHAMe predictions and observations for both cosmologies, indicating that the lensing-is-low problem originates from approximations in previous theoretical descriptions of the data. The main difference between SHAMe results in these cosmologies is the level of galaxy assembly bias, which is approximately 20 and 10% for Planck and Low S8, respectively. These results highlight the dangers of employing oversimplified models to analyse current large-scale structure datasets, and the need for realistic yet flexible descriptions of the galaxy-halo connection.

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S. Contreras, J. Chaves-Montero and R. Angulo
Wed, 17 May 23
16/67

Comments: 13 pages, 9 figures. Submitted to MNRAS

Map-based studies on how the CMB shadow degrades tensor-to-scalar ratio measurements and how to mitigate it [CEA]

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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

Is there an excess of black holes around $20 M_{\odot}$? Optimising the complexity of population models with the use of reversible jump MCMC [CL]

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http://arxiv.org/abs/2305.08909


Some analyses of the third gravitational wave catalogue released by the LIGO-Virgo-KAGRA collaboration (LVK) suggest an excess of black holes around $15-20 M_{\odot}$. In order to investigate this feature, we introduce two flexible population models, a semi-parametric one and a non-parametric one. Both make use of reversible jump Markov chain Monte-Carlo to optimise their complexity. We also illustrate how the latter can be used to efficiently perform model selection. Our parametric model broadly agrees with the fiducial analysis of the LVK, but finds a peak of events at slightly larger masses. Our non-parametric model shows this same displacement. Moreover, it also suggests the existence of an excess of black holes around $20 M_{\odot}$. We assess the robustness of this prediction by performing mock injections and running hierarchical analyses on those. We find that such a feature might be due to statistical fluctuations, given the small number of events observed so far, with a $5\%$ probability. We estimate that with a few hundreds of observations, as expected for O4, our non-parametric model will, be able to robustly determine the presence of this excess. It will then allow for an efficient agnostic inference of the properties of black holes.

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A. Toubiana, M. Katz and J. Gair
Wed, 17 May 23
18/67

Comments: 8 pages, 6 figures

Cosmology of Single Species Hidden Dark Matter [CEA]

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http://arxiv.org/abs/2305.08943


Cosmology and astrophysics provide various ways to study the properties of dark matter even if they have negligible non-gravitational interactions with the Standard Model particles and remain hidden. We study a type of hidden dark matter model in which the dark matter is completely decoupled from the Standard Model sector except gravitationally, and consists of a single species with a conserved comoving particle number. This category of hidden dark matter includes models that act as warm dark matter but is more general. In particular, in addition to having an independent temperature from the Standard Model sector, it includes cases in which dark matter is in its own thermal equilibrium or is free-streaming, obeys fermionic or bosonic statistics, and processes a chemical potential that controls the particle occupation number. While the usual parameterization using the free-streaming scale or the particle mass no longer applies, we show that all cases can be well approximated by a set of functions parameterized by only one parameter as long as the chemical potential is nonpositive: the characteristic scale factor at the time of the relativistic-to-nonrelativistic transition. We study the constraints from Big Bang Nucleosynthesis, the cosmic microwave background, the Lyman-$\alpha$ forest, and the smallest halo mass. We show that the most significant phenomenological impact is the suppression of the small-scale matter power spectrum — a typical feature when the dark matter has a velocity dispersion or pressure at early times. So far, small dark matter halos provide the strongest constraint, limiting the transition scale factor to be no larger than $\sim1.4\times10^{-4}$ times the scale factor at matter-radiation equality.

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W. Lin, X. Chen, H. Ganjoo, et. al.
Wed, 17 May 23
21/67

Comments: 24 pages, 3 tables, 8 figures, comments welcome

How to estimate Fisher matrices from simulations [CL]

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http://arxiv.org/abs/2305.08994


The Fisher information matrix is a quantity of fundamental importance for information geometry and asymptotic statistics. In practice, it is widely used to quickly estimate the expected information available in a data set and guide experimental design choices. In many modern applications, it is intractable to analytically compute the Fisher information and Monte Carlo methods are used instead. The standard Monte Carlo method produces estimates of the Fisher information that can be biased when the Monte-Carlo noise is non-negligible. Most problematic is noise in the derivatives as this leads to an overestimation of the available constraining power, given by the inverse Fisher information. In this work we find another simple estimate that is oppositely biased and produces an underestimate of the constraining power. This estimator can either be used to give approximate bounds on the parameter constraints or can be combined with the standard estimator to give improved, approximately unbiased estimates. Both the alternative and the combined estimators are asymptotically unbiased so can be also used as a convergence check of the standard approach. We discuss potential limitations of these estimators and provide methods to assess their reliability. These methods accelerate the convergence of Fisher forecasts, as unbiased estimates can be achieved with fewer Monte Carlo samples, and so can be used to reduce the simulated data set size by several orders of magnitude.

Read this paper on arXiv…

W. Coulton and B. Wandelt
Wed, 17 May 23
29/67

Comments: Supporting code available at this https URL

Optimizing the Evolution of Perturbations in the $Λ$CDM Universe [CEA]

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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

Quasinormal modes and grey-body factors of regular black holes with a scalar hair from the Effective Field Theory [CL]

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http://arxiv.org/abs/2305.09187


The Effective Field Theory (EFT) of perturbations on an arbitrary background geometry with a timelike scalar profile has been recently constructed in the context of scalar-tensor theories. Unlike General Relativity, the regular Hayward metric is realized as an exact background metric in the Effective Field Theory with timelike scalar profile without resorting to special matter field, such as nonlinear electrodynamics. The fundamental quasinormal mode for axial graviational perturbations of this black hole has been considered recently with the help of various methods. Here we make a further step in this direction and find that, unlike the fundamental mode, a few first overtones deviate from their Schwarzschild limit at a much higher rate. This outburst of overtones occurs because the overtones are extremely sensitive to the least change of the near-horizon geometry. The analytical formula for quasinormal modes is obtained in the eikonal regime. In addition, we calculated grey-body factors and showed that regular Hayward black hole with a scalar hair has smaller grey-body factor than the Schwarzschild one. Integration of the wave-like equation in time-domain shows that the power-law tails following the ring-down phase at late times are indistinguishable from the Schwarzschild ones.

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R. Konoplya
Wed, 17 May 23
32/67

Comments: 9 pages, revtex, 3 figures

A Geometric Calibration of the Tip of the Red Giant Branch in the Milky Way using Gaia DR3 [GA]

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http://arxiv.org/abs/2305.09215


We use the latest parallaxes measurements from Gaia DR3 to obtain a geometric calibration of the tip of the red giant branch (TRGB) in Cousins $I$ magnitudes as a standard candle for cosmology. We utilise the following surveys: SkyMapper DR3, APASS DR9, ATLAS Refcat2, and Gaia DR3 synthetic photometry to obtain multiple zero-point calibrations of the TRGB magnitude, $M_{I}^{TRGB}$. Our sample contains Milky Way halo stars at high galactic latitudes ($|b| > 36$) where the impact of metallicity, dust, and crowding are minimised. The magnitude of the TRGB is identified using Sobel edge detection, but this approach introduced a systematic offset. To address this issue, we utilised simulations with PARSEC isochrones and showed how to calibrate and remove this bias. Applying our method within the colour range where the slope of the TRGB is relatively flat for metal-poor halo stars (1.55 $<$ $(BP-RP)$ $<$ 2.25), we find a weighted average $M_{I}^{TRGB} = -4.042 \pm 0.041$ (stat) $\pm0.031$ (sys) mag. A geometric calibration of the Milky Way TRGB has the benefit of being independent of other distance indicators and will help probe systematics in the local distance ladder, leading to improved measurements of the Hubble constant.

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M. Dixon, J. Mould, C. Flynn, et. al.
Wed, 17 May 23
33/67

Comments: 14 pages, 13 figures. Accepted for publication in MNRAS

Planting a Lyman alpha forest on AbacusSummit [CEA]

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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.

Read this paper on arXiv…

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

Primordial black holes and inflation from double-well potentials [CEA]

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http://arxiv.org/abs/2305.09630


We investigate the formation of large peaks in the inflationary curvature power spectrum from double-well potentials. In such scenarios, the initial CMB spectrum is created at large field values. Subsequently, the inflaton will cross one of the minima and will decelerate rapidly as it reaches the local maximum at the origin, either falling back or crossing it. During this final phase, a significant peak in the curvature power spectrum can be generated. Our analysis reveals that this class of models produces more pronounced peaks than the more commonly studied quasi-inflection point scenarios with less tuning for the model parameters. Finally, we construct an explicit theoretically motivated inflationary scenario that is consistent with the latest CMB observations and capable of generating sufficiently large curvature perturbations for primordial black holes.

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A. Karam, N. Koivunen, E. Tomberg, et. al.
Wed, 17 May 23
44/67

Comments: 22 pages, 5 figures

Cold New Early Dark Energy pulls the trigger on the $H_0$ and $S_8$ tensions: a simultaneous solution to both tensions without new ingredients [CEA]

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http://arxiv.org/abs/2305.08895


In this work, we show that the Cold New Early Dark Energy (Cold NEDE) model in its original form can solve both the Hubble tension and the $S_8$ tension without adding any new ingredients at the fundamental level. So far, it was assumed that the trigger field in the Cold NEDE model is completely subdominant. However, relaxing this assumption and letting the trigger field contribute a mere $0.5\%$ of the total energy density leads to a resolution of the $S_8$ tension while simultaneously improving it as a solution to the $H_0$ tension. Fitting this model to baryonic acoustic oscillations, large-scale-structure, supernovae (including a SH0ES prior), and cosmic microwave background data, we report a preferred NEDE fraction of $f_\mathrm{NEDE}= 0.134^{+0.032}_{-0.025}$ ($68\%$ C.L.), lifting its Gaussian evidence for the first time above $5\sigma$ (up from $4 \sigma$ when the trigger contribution to dark matter is negligible). At the same time, we find the new concordance values $H_0 = 71.71 \pm 0.88 \,\mathrm{km}\, \mathrm{sec}^{-1}\, \mathrm{Mpc}^{-1}$ and $S_8 = 0.793 \pm 0.018$. Excluding large-scale structure data and the SH$_0$ES prior, both Gaussian tensions are reduced below the $2 \sigma$ level.

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J. Cruz, F. Niedermann and M. Sloth
Wed, 17 May 23
46/67

Comments: 40 pages, 7 figures, 8 tables

The uncertainties on the EFT coupling limits for direct dark matter detection experiments stemming from uncertainties of target properties [CL]

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http://arxiv.org/abs/2305.08991


Direct detection experiments are still one of the most promising ways to unravel the nature of dark matter. To fully understand how well these experiments constrain the dark matter interactions with the Standard Model particles, all the uncertainties affecting the calculations must be known. It is especially critical now because direct detection experiments recently moved from placing limits only on the two elementary spin independent and spin dependent operators to the complete set of possible operators coupling dark matter and nuclei in non-relativistic theory. In our work, we estimate the effect of nuclear configuration-interaction uncertainties on the exclusion bounds for one of the existing xenon-based experiments for all fifteen operators. We find that for operator number 13 the $\pm1\sigma$ uncertainty on the coupling between the dark matter and nucleon can reach more than 50% for dark matter masses between 10 and 1000 GeV. In addition, we discuss how quantum computers can help to reduce this uncertainty.

Read this paper on arXiv…

D. Heimsoth, B. Lem, A. Suliga, et. al.
Wed, 17 May 23
49/67

Comments: 12 pages, 6 figures

(Non)Null results of time-varying $α$ in the meVSL [CEA]

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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.

Read this paper on arXiv…

S. Lee
Wed, 17 May 23
55/67

Comments: 10 pages

Frequency-Domain Distribution of Astrophysical Gravitational-Wave Backgrounds [CEA]

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http://arxiv.org/abs/2305.09372


The superposition of many astrophysical gravitational waves (GW) signals below typical detection thresholds baths detectors in a stochastic gravitational wave background (SGWB). In this work we present a Fourier space approach to compute the frequency-domain distribution of stochastic gravitational wave backgrounds produced by discrete sources. The expressions for the moment generating function and the distribution of observed (discrete) Fourier modes are provided. The results are then applied to the SGWB originating from the mergers of compact stellar remnants (black holes and neutron stars) in the Universe, which are found to exhibit a $-4$ power-law tail. This tail is verified in the signal-to-noise ratio distribution of GWTC events. Furthermore, the extent to which the subtraction of bright (loud) mergers gaussianizes the resulting confusion noise of unresolved sources is illustrated. The power-law asymptotic tail for the SGWB, and an exponentially decaying tail in the case of the confusion background, are also derived analytically. Our results generalize to any background of gravitational waves emanating from discrete sources.

Read this paper on arXiv…

Y. Ginat, R. Reischke, I. Rapoport, et. al.
Wed, 17 May 23
58/67

Comments: Comments welcome

An Auto-Differentiable Likelihood Pipeline for the Cross-Correlation of CMB and Large-Scale Structure due to the Kinetic Sunyaev-Zeldovich Effect [CEA]

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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.

Read this paper on arXiv…

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

Comments: 26 pages, 9 figures

A short survey of matter-antimatter evolution in the primordial universe [CL]

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http://arxiv.org/abs/2305.09055


We offer a survey of the matter-antimatter evolution within the primordial Universe. While the origin of the tiny matter-antimatter asymmetry has remained one of the big questions in modern cosmology, antimatter itself has played a large role for much of the Universe’s early history. In our study of the evolution of the Universe we adopt the position of the standard model $\Lambda$-CDM Universe implementing the known baryonic asymmetry. We present the composition of the Universe across its temperature history while emphasizing the epochs where antimatter content is essential to our understanding. Special topics we address include the heavy quarks in quark-gluon plasma (QGP), the creation of matter from QGP, the free-streaming of the neutrinos, the vanishing of the muons, the magnetism in the electron-positron cosmos, and a better understanding of the environment of the Big Bang Nucleosynthesis (BBN) producing the light elements. We suggest but do not explore further that the methods used in exploring the early Universe may also provide new insights in the study of exotic stellar cores, magnetars, as well as gamma-ray burst (GRB) events. We describe future investigations required in pushing known physics to its extremes in the unique laboratory of the matter-antimatter early Universe.

Read this paper on arXiv…

J. Rafelski, J. Birrell, A. Steinmetz, et. al.
Wed, 17 May 23
67/67

Comments: 46 pages, 26 figures

On the Decoherence of Primordial Gravitons [CL]

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http://arxiv.org/abs/2305.08071


It is well-known that the primordial scalar curvature and tensor perturbations, $\zeta$ and $\gamma_{ij}$, are conserved on super-horizon scales in minimal inflation models. However, their wave functional has a rapidly oscillating phase which is slow-roll unsuppressed, as can be seen either from boundary (total-derivative) terms of cosmological perturbations, or the WKB approximation of the Wheeler-DeWitt equation. Such an oscillatory phase involves gravitational non-linearity between scalar and tensor perturbations. By tracing out unobserved modes, the oscillatory phase causes faster decoherence of primordial gravitons compared to those by bulk interactions. Our results put a stronger lower bound of decoherence effect to the recent proposals probing squeezed primordial gravitons.

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S. Ning, C. Sou and Y. Wang
Tue, 16 May 23
2/83

Comments: 42 pages, 3 figures, 1 table

Dissipative Inflation via Scalar Production [CL]

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http://arxiv.org/abs/2305.07695


We describe a new mechanism that gives rise to dissipation during cosmic inflation. In the simplest implementation, the mechanism requires the presence of a massive scalar field with a softly-broken global $U(1)$ symmetry, along with the inflaton field. Particle production in this scenario takes place on parametrically sub-horizon scales, at variance with the case of dissipation into gauge fields. Consequently, the backreaction of the produced particles on the inflationary dynamics can be treated in a \textit{local} manner, allowing us to compute their effects analytically. We determine the parametric dependence of the power spectrum which deviates from the usual slow-roll expression. Non-Gaussianities are always sizeable whenever perturbations are generated by the noise induced by dissipation: $f_{\rm NL}^{\rm eq} \gtrsim {O}(10)$.

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P. Creminelli, S. Kumar, B. Salehian, et. al.
Tue, 16 May 23
6/83

Comments: 31 pages + appendices, 8 figures

Dynamics of false vacuum bubbles with trapped particles [CL]

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http://arxiv.org/abs/2305.07702


We study the impact of the ambient fluid on the evolution of collapsing false vacuum bubbles by simulating the dynamics of a coupled bubble-particle system. A significant increase in the mass of the particles across the bubble wall leads to a buildup of those particles inside the false vacuum bubble. We show that the backreaction of the particles on the bubble slows or even reverses the collapse. Consequently, if the particles in the true vacuum become heavier than in the false vacuum, the particle-wall interactions always decrease the compactness that the false vacuum bubbles can reach making their collapse to black holes less likely.

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M. Lewicki, K. Müürsepp, J. Pata, et. al.
Tue, 16 May 23
17/83

Comments: 13 pages, 7 figures

Extinction biases quasar luminosity distances determined from quasar UV and X-ray flux measurements [GA]

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http://arxiv.org/abs/2305.08179


A sample of X-ray detected reverberation-mapped quasars provides a unique opportunity to compare cosmological constraints inferred using two well-established relations – the X-ray/UV luminosity ($L_{X}-L_{UV}$) relation and the broad-line region radius-UV monochromatic luminosity ($R-L$) relation. $L_{X}-L_{UV}$ and $R-L$ luminosity distances to the same quasars exhibit a distribution of their differences that is generally positively skewed for the six cosmological models we consider. This behaviour can be interpreted qualitatively to arise as a result of the dust extinction of UV/X-ray quasar emission. We show that the extinction always contributes to the non-zero difference between $L_{X}-L_{UV}$-based and $R-L$-based luminosity distances and we derive a linear relationship between the X-ray/UV colour index $E_{X-UV}$ and the median/mean value of the luminosity-distance difference, which also depends on the value of the $L_{X}-L_{UV}$ relation slope. Taking into account the prevailing positive values of the luminosity-distance difference median, we estimate an average X-ray/UV colour index of $\overline{E}{X-UV}=0.089 \pm 0.019$ mag, while the value based on the positive mean values of the difference is $\overline{E}{X-UV}=0.050\pm 0.013$ mag. We demonstrate that this amount of extinction is typical for the majority of quasars since it originates in the circumnuclear and interstellar media of host galaxies. It can only be slightly alleviated by the standard hard X-ray and far-UV extinction cuts used by Lusso et al. (2020). Consequently, the $L_{X}-L_{UV}$ relation QSO data compilation of Lusso et al. (2020) cannot be used for cosmological purposes.

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M. Zajaček, B. Czerny, N. Khadka, et. al.
Tue, 16 May 23
19/83

Comments: 12 pages, 7 figures, 3 tables; submitted to the MNRAS Main Journal, comments welcome

Exploring Ultralight Scalar Assistance in Sterile Neutrino Dark Matter: Cold Spectrum and Unusual X/Gamma-ray Signatures [CL]

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http://arxiv.org/abs/2305.08095


We present a scalar-driven sterile neutrino production model where the interaction with the ultralight scalar field modifies the oscillation production of sterile neutrinos in the early universe. The model effectively suppresses the production of sterile neutrinos at low temperatures due to the heavy scalar mass, resulting in a colder matter power spectrum that avoids constraints from small-scale structure observations. In this model, the dominant dark matter relic is from sterile neutrinos, with only a small fraction originating from the ultralight scalar. Furthermore, the model predicts a detectable X/Gamma-ray flux proportional to the cubic density of local sterile neutrinos for a light scalar mass due to the light scalar coupling tosterile neutrinos. This distinguishes our model from normal decaying dark matter, which has a linear dependence on the density. In addition, the model predicts a potential low-energy monochromatic neutrino signal that can be detectable by future neutrino telescopes.

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Y. He, J. Liu, X. Ma, et. al.
Tue, 16 May 23
20/83

Comments: 15 pages, 5 figures

Measuring $H_0$ with Spectroscopic Surveys [CEA]

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http://arxiv.org/abs/2305.07977


Galaxy surveys map the three-dimensional distribution of matter in the Universe, encoding information about both the primordial cosmos and its subsequent evolution. By comparing the angular and physical scales of features in the galaxy distribution, we can compute the physical distance to the sample, and thus extract the Hubble parameter, $H_0$. In this chapter, we discuss how this is performed in practice, introducing two key standard rulers''. The first, the sound horizon at recombination, leads to baryon acoustic oscillations, and, by combining with external data from the CMB or Big Bang Nucleosynthesis, leads to a competitive $H_0$ constraint. Information can also be extracted from the physical scale of the horizon at matter-radiation equality; though somewhat less constraining, this depends on very different physics and is an important validation test of the physical model. We discuss how both such constraints can be derived (usingtemplate” and “full-shape” methodologies), and present a number of recent constraints from the literature, some of which are comparable in precision to (and independent from) Planck. Finally, we discuss future prospects for improving these constraints in the future.

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M. Ivanov and O. Philcox
Tue, 16 May 23
21/83

Comments: Invited chapter for the edited book “Hubble Constant Tension” (Eds. E. Di Valentino and D. Brout, Springer Singapore, expected in 2024)

Two-body problem in theories with kinetic screening [CL]

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http://arxiv.org/abs/2305.07725


New light scalar degrees of freedom may alleviate the dark matter and dark energy problems, but if coupled to matter, they generally mediate a fifth force. In order for this fifth force to be consistent with existing constraints, it must be suppressed close to matter sources, e.g. through a non-linear screening mechanism. In this work, we investigate the non-relativistic two-body problem in shift-symmetric scalar-tensor theories that exhibit kinetic screening ($k$-mouflage), both numerically and analytically. We develop an approximate scheme, based on a Hodge-Helmholtz decomposition of the Noether current associated to the shift symmetry, allowing for a qualitative insight into the dynamics and yielding results in good agreement with the numerical ones in most of the parameter space. We apply the formalism to polynomial $k$-essence and to Dirac-Born-Infeld (DBI) type theories, as well as to theories that develop “anti-screening”. In the deep nonlinear regime, we find that the fifth force is screened slightly more efficiently in equal-mass systems than in extreme mass-ratio ones. However, we find that systems with comparable masses also exhibit regions where the screening is ineffective. These descreened spheroidal regions (bubbles) could in principle be probed in the solar system with sufficiently precise space accelerometers.

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M. Bošković and E. Barausse
Tue, 16 May 23
28/83

Comments: 16+5 pages; 13 figures

A Novel Cosmological Joint Constraints in Multidimensional Observables Space with Redshift-free Inferences [CEA]

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http://arxiv.org/abs/2305.08047


Cosmology constraints serve as a crucial criterion in discriminating cosmological models. The traditional combined method to constrain the cosmological parameters designates the corresponding theoretical value and observational data as functions of redshift, however, sometimes the redshift cannot be measured directly, or the measurement error is large, or the definition of redshift is controversial. In this paper, we propose a novel joint method to constrain parameters that eliminates the redshift $z$ and makes full use of the multiple observables $\left\lbrace \mathcal{F}{1,\mathrm{obs}},\mathcal{F}{2,\mathrm{obs}},\cdots,\mathcal{F}{M,\mathrm{obs}}\right\rbrace$ spanning in $M$-dimensional joint observables space. Considering the generality of the mathematical form of the cosmological models and the guidance from low to high dimensions, we firstly validate our method in a three-dimensional joint observables space spanned by $H(z)$, $f\sigma{8}(z)$ and $D_{A}(z)$, where the three coordinates can be considered redshift-free measurements of the same celestial body (or shared-redshift data reconstructed model independently). Our results are consistent with the traditional combined method but with lower errors, yielding $H_0=68.7\pm0.1\mathrm{~km} \mathrm{~s}^{-1}\mathrm{~Mpc}^{-1}$, $\Omega_{m0}=0.289\pm0.003$, $\sigma_{8}=0.82\pm0.01$ and showing alleviated parametric degeneracies to some extent. In principle, our joint constraint method allows an extended form keeping the redshift information as an independent coordinate and can also be readily degraded to the form of a traditional combined method to constrain parameters.

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W. Hong, K. Jiao, Y. Wang, et. al.
Tue, 16 May 23
33/83

Comments: 16 pages, 12 figures, 4 tables, Submitted to Astrophysical Journal Supplement

Role of Future SNIa Data from LSST in Reinvestigating Cosmological Models [CEA]

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http://arxiv.org/abs/2305.08786


We study how future Type-Ia supernovae (SNIa) standard candles detected by the Vera C. Rubin Observatory (LSST) can constrain some cosmological models. We use a realistic three-year SNIa simulated dataset generated by the LSST Dark Energy Science Collaboration (DESC) Time Domain pipeline, which includes a mix of spectroscopic and photometrically identified candidates. We combine this data with Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillation (BAO) measurements to estimate the dark energy model parameters for two models- the baseline $\Lambda$CDM and Chevallier-Polarski-Linder (CPL) dark energy parametrization. We compare them with the current constraints obtained from joint analysis of the latest real data from the Pantheon SNIa compilation, CMB from Planck 2018 and BAO. Our analysis finds tighter constraints on the model parameters along with a significant reduction of correlation between $H_0$ and $\sigma_8$. We find that LSST is expected to significantly improve upon the existing SNIa data in the critical analysis of cosmological models.

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R. Shah, A. Mitra, P. Mukherjee, et. al.
Tue, 16 May 23
34/83

Comments: 8 pages, 5 figures

First stars signatures in high-z absorbers [GA]

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http://arxiv.org/abs/2305.07706


The first stars were likely more massive than those forming today and thus rapidly evolved, exploding as supernovae and enriching the surrounding gas with their chemical products. In the Local Group, the chemical signature of the first stars has been identified in the so-called Carbon-Enhanced Metal-Poor stars (CEMP-no). On the contrary, a similar C-excess was not found in dense neutral gas traced by high-redshift absorption systems. Here we discuss the recent discovery of three C-enhanced very metal-poor ([Fe/H]< -2) optically thick absorbers at redshift z ~ 3-4, reported by (Saccardi et al. 2023). We show that these absorbers are extra-galactic tracers of the chemical signatures of the first stars, analogous to the CEMP-no stars observed in the Galactic halo and ultra-faint dwarf galaxies. Furthermore, by comparing observations with model predictions we demonstrate that these systems have most likely been imprinted by first stars exploding as low-energy supernovae, which provided > 50% of the metals in these absorbers

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S. Salvadori, V. D’Odorico, A. Saccardi, et. al.
Tue, 16 May 23
35/83

Comments: Mem. S.A.It. in press

Pulsar timing residual induced by ultralight tensor dark matter [CL]

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http://arxiv.org/abs/2305.08091


Ultralight boson fields, with a mass around $10^{-23}\text{eV}$, are promising candidates for the elusive cosmological dark matter. These fields induce a periodic oscillation of the spacetime metric in the nanohertz frequency band, which is detectable by pulsar timing arrays. In this paper, we investigate the gravitational effect of ultralight tensor dark matter on the arrival time of radio pulses from pulsars. We find that the pulsar timing signal caused by tensor dark matter exhibits a different angular dependence than that by scalar and vector dark matter, making it possible to distinguish the ultralight dark matter signal with different spins. Combining the gravitational effect and the coupling effect of ultralight tensor dark matter with standard model matter provides a complementary way to constrain the coupling parameter $\alpha$. We estimate $\alpha \lesssim 10^{-6}\sim 10^{-5}$ in the mass range $m<5\times 10^{-23}\mathrm{eV}$ with current pulsar timing array.

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Y. Wu, Z. Chen and Q. Huang
Tue, 16 May 23
45/83

Comments: 12 pages, 3 figures

Halos of dark energy [CEA]

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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)

Precision cosmology with the 21-cm signal from the dark ages [CEA]

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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

Is Cosmic Birefringence model-dependent? [CEA]

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http://arxiv.org/abs/2305.07937


Exciting clues to isotropic cosmic birefringence have recently been detected in the $EB$ cross-power spectra of the polarization data of the cosmic microwave background (CMB). Early Dark Energy (EDE) models with a pseudoscalar field coupled to photons via a Chern-Simons term can be used to explain this phenomenon, and can also potentially be used to simultaneously resolve the $H_0$ tension. In this work we incorporate an early dark energy scalar field, including a Chern-Simons coupling, into an existing Boltzmann solver and numerically recover the $EB$ cross-power spectrum for two models in the literature; the $\alpha$-attractor, and the Rock `n’ Roll field. We find that both the models fit the $EB$ spectra, and the $EB$ spectra alone do not possess sufficient constraining power to distinguish the two models based on current data.

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L. Yin, J. Kochappan, T. Ghosh, et. al.
Tue, 16 May 23
60/83

Comments: N/A

Probing bursty star formation by cross-correlating extragalactic background light and galaxy surveys [GA]

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http://arxiv.org/abs/2305.08847


Understanding the star formation rate (SFR) variability and how it depends on physical properties of galaxies is important for developing and testing the theory of galaxy formation. We investigate how statistical measurements of the extragalactic background light (EBL) can shed light on this topic and complement traditional methods based on observations of individual galaxies. Using semi-empirical models of galaxy evolution and SFR indicators sensitive to different star formation timescales (e.g., H$\alpha$ and UV continuum luminosities), we show that the SFR variability, quantified by the joint probability distribution of the SFR indicators (i.e., the bivariate conditional luminosity function), can be characterized as a function of galaxy mass and redshift through the cross-correlation between deep, near-infrared maps of the EBL and galaxy distributions. As an example, we consider combining upcoming SPHEREx maps of the EBL with galaxy samples from Rubin/LSST. We demonstrate that their cross-correlation over a sky fraction of $f_\mathrm{sky}\sim0.5$ can constrain the joint SFR indicator distribution at high significance up to $z\sim2.5$ for mass-complete samples of galaxies down to $M_{*}\sim10^9\,M_{\odot}$. These constraints not only allow models of different SFR variability to be distinguished, but also provide unique opportunities to investigate physical mechanisms that require large number statistics such as environmental effects. The cross-correlations investigated illustrate the power of combining cosmological surveys to extract information inaccessible from each data set alone, while the large galaxy populations probed capture ensemble-averaged properties beyond the reach of targeted observations towards individual galaxies.

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G. Sun, A. Lidz, A. Faisst, et. al.
Tue, 16 May 23
62/83

Comments: 12 pages, 7 figures, submitted to MNRAS; comments welcome

Neutrino forces and experimental probes [CL]

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http://arxiv.org/abs/2305.08032


Neutrinos as almost massless particles could mediate long-range forces, known as neutrino forces. In this talk, I will introduce some theoretical aspects of neutrino forces, including why the potential of a neutrino force has the $1/r^{5}$ form and how it may vary under different circumstances. Experimental probes and possible implications for cosmology are also briefly discussed.

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X. Xu
Tue, 16 May 23
74/83

Comments: 6 pages, 4 figures, Contribution to the 2023 Electroweak session of the 57th Rencontres de Moriond

Abelian-Higgs cosmic strings: effective action and particle radiation [CL]

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http://arxiv.org/abs/2305.08155


We utilized the duality between massive vector and massive Kalb-Ramond fields to derive an effective action for Abelian-Higgs cosmic strings. This enabled us to determine the classically renormalized string tension and facilitate calculations for back-reaction effects. Additionally, we derived a comprehensive expression for the energy flux of radiation emitted by Abelian-Higgs cosmic strings. Applying this equation to a cuspless loop, we obtained that the loop lifetime is proportional to the square of the loop length, which is in agreement with field-theory simulations.

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I. Rybak
Tue, 16 May 23
77/83

Comments: 14 pages, 1 figure

The Two Quasi-Static Limits of Aether Scalar Tensor Theory [CL]

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http://arxiv.org/abs/2305.07742


One of the aims of Aether Scalar Tensor Theory (AeST) is to reproduce the successes of Modified Newtonian Dynamics (MOND) on galactic scales. Indeed, the quasi-static limit of AeST can achieve precisely this, assuming that the vector field $\vec{A}$ vanishes. However, this assumption of a vanishing vector field is often inconsistent. Here, we show how to correctly take into account the vector field and find that the quasi-static limit depends on a model parameter $m_\times$. In the limit $m_\times \to 0$, one recovers the quasi-static limit with a vanishing vector field. In particular, one finds a two-field version of MOND. In the opposite limit, $m_\times \to \infty$, one finds a single-field version of MOND. We show that, in practice, much of the phenomenology of the quasi-static limit depends only very little on the value of $m_\times$. Still, for some observational tests, such as those involving wide binaries, $m_\times$ has percent-level effects that may be important.

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T. Mistele
Tue, 16 May 23
80/83

Comments: 24 pages, 4 figures

The Spitzer Extragalactic Representative Volume Survey and DeepDrill extension: clustering of near-infrared galaxies [CEA]

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http://arxiv.org/abs/2305.07464


We have measured the angular auto-correlation function of near-infrared galaxies in SERVS+DeepDrill, the Spitzer Extragalactic Representative Volume Survey and its follow-up survey of the Deep Drilling Fields, in three large fields totalling over 20 sq. deg on the sky, observed in two bands centred on 3.6 and 4.5 micron. We performed this analysis on the full sample as well as on sources selected by [3.6]-[4.5] colour in order to probe clustering for different redshift regimes. We estimated the spatial correlation strength as well, using the redshift distribution from S-COSMOS with the same source selection. The strongest clustering was found for our bluest subsample, with z~0.7, which has the narrowest redshift distribution of all our subsamples. We compare these estimates to previous results from the literature, but also to estimates derived from mock samples, selected in the same way as the observational data, using deep light-cones generated from the SHARK semi-analytical model of galaxy formation. For all simulated (sub)samples we find a slightly steeper slope than for the corresponding observed ones, but the spatial clustering length is comparable in most cases.

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E. Kampen, M. Lacy, D. Farrah, et. al.
Mon, 15 May 23
2/53

Comments: 20 pages, 15 figures, 6 tables, accepted for publication in MNRAS

Dynamic Dark Energy from the Local Limit of Nonlocal Gravity [CL]

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http://arxiv.org/abs/2305.07630


Nonlocal gravity (NLG), a classical extension of Einstein’s theory of gravitation, has been studied mainly in linearized form. In particular, nonlinearities have thus far prevented the treatment of cosmological models in NLG. In this essay, we discuss the local limit of NLG and apply this limit to the expanding homogenous and isotropic universe. The theory only allows spatially flat cosmological models; furthermore, de Sitter spacetime is forbidden. The components of the model will have different dynamics with respect to cosmic time as compared to the standard $\Lambda$CDM model; specifically, instead of the cosmological constant, the modified flat model of cosmology involves a dynamic dark energy component in order to account for the accelerated phase of the expansion of the universe.

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J. Tabatabaei, A. Banihashemi, S. Baghram, et. al.
Mon, 15 May 23
3/53

Comments: Honorable Mention in the Gravity Research Foundation 2023 Awards for Essays on Gravitation

Dynamic Dark Energy from the Local Limit of Nonlocal Gravity [CL]

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http://arxiv.org/abs/2305.07630


Nonlocal gravity (NLG), a classical extension of Einstein’s theory of gravitation, has been studied mainly in linearized form. In particular, nonlinearities have thus far prevented the treatment of cosmological models in NLG. In this essay, we discuss the local limit of NLG and apply this limit to the expanding homogenous and isotropic universe. The theory only allows spatially flat cosmological models; furthermore, de Sitter spacetime is forbidden. The components of the model will have different dynamics with respect to cosmic time as compared to the standard $\Lambda$CDM model; specifically, instead of the cosmological constant, the modified flat model of cosmology involves a dynamic dark energy component in order to account for the accelerated phase of the expansion of the universe.

Read this paper on arXiv…

J. Tabatabaei, A. Banihashemi, S. Baghram, et. al.
Mon, 15 May 23
3/53

Comments: Honorable Mention in the Gravity Research Foundation 2023 Awards for Essays on Gravitation

NIKA2 Cosmological Legacy Survey: Survey Description and Galaxy Number Counts [GA]

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http://arxiv.org/abs/2305.07054


Aims. Deep millimeter surveys are necessary to probe the dust-obscured galaxies at high redshift. We conducted a large observing program at 1.2 and 2 mm with the NIKA2 camera installed on the IRAM 30-meter telescope. This NIKA2 Cosmological Legacy Survey (N2CLS) covers two emblematic fields: GOODS-N and COSMOS. We introduce the N2CLS survey and present new 1.2 and 2 mm number count measurements based on the tiered N2CLS observations from October 2017 to May 2021.
Methods. We develop an end-to-end simulation that combines an input sky model with the instrument noise and data reduction pipeline artifacts. This simulation is used to compute the sample purity, flux boosting, pipeline transfer function, completeness, and effective area of the survey. We used the 117 deg$^2$ SIDES simulations as the sky model, which include the galaxy clustering. Our formalism allows us to correct the source number counts to obtain galaxy number counts, the difference between the two being due to resolution effects caused by the blending of several galaxies inside the large beam of single-dish instruments.
Results. The N2CLS-May2021 survey reaches an average 1-$\sigma$ noise level of 0.17 and 0.048 mJy on GOODS-N over 159 arcmin$^2$, and 0.46 and 0.14 mJy on COSMOS over 1010 arcmin$^2$, at 1.2 and 2 mm, respectively. For a purity threshold of 80%, we detect 120 and 67 sources in GOODS-N and 195 and 76 sources in COSMOS, at 1.2 and 2 mm, respectively. Our measurement connects the bright single-dish to the deep interferometric number counts. After correcting for resolution effects, our results reconcile the single-dish and interferometric number counts and are further accurately compared with model predictions.

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L. Bing, M. Béthermin, G. Lagache, et. al.
Mon, 15 May 23
15/53

Comments: Accepted by A&A. 23 pages, 12 figures

On the nature of M31 gamma-ray halo in its relation to dark matter annihilation [HEAP]

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http://arxiv.org/abs/2305.07590


The present work analyzes various aspects of M31 gamma-ray halo emission in its relation to annihilating dark matter (DM). The main aspect is the predicted effect of asymmetry of the intensity of emission due to inverse Compton scattering (ICS) of a possible population of relativistic electrons and positrons ($e^\pm$) in the galactic halo on starlight photons. This asymmetry is expected to exist around the major galactic axis, and arises due to anisotropy of the interstellar radiation field and the inclination of M31. ICS emission and its asymmetry were modeled by GALPROP code for the trial case of $e^\pm$ generated by annihilating weakly interacting massive particles (WIMPs) with various properties. The asymmetry was obtained to appear at photon energies above $\sim$ 0.1 MeV. Morphological and spectral properties of the asymmetry were studied in detail. Potential observational detection of the asymmetry may allow to infer the leptonic fraction in the emission generation mechanism, thus providing valuable inferences for understanding the nature of M31 gamma-ray halo emission. Specific asymmetry predictions were made for the recently claimed DM interpretation of the outer halo emission. The paper also studied the role of secondary — ICS and bremsstrahlung — emissions due to DM annihilation for that interpretation. And, finally, the latter was shown to be in significant tension with the recently derived WIMP constraints by radio data on M31.

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A. Egorov
Mon, 15 May 23
16/53

Comments: 15 pages, 5 figures, 4 tables, submitted to Phys. Rev. D

Insights from HST into Ultra-Massive Galaxies and Early-Universe Cosmology [CEA]

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http://arxiv.org/abs/2305.07049


The early-science observations made by the James Webb Space Telescope (JWST) have revealed an excess of ultra-massive galaxy candidates that appear to challenge the standard cosmological model ($\Lambda$CDM). Here, we argue that any modifications to $\Lambda$CDM that can produce such ultra-massive galaxies in the early Universe would also affect the UV galaxy luminosity function (UV LF) inferred from the Hubble Space Telescope (HST). The UV LF covers the same redshifts ($z\approx 7-10$) and host-halo masses $(M_\mathrm{h}\approx 10^{10}-10^{12}\, M_\odot$) as the JWST candidates, but tracks star-formation rate rather than stellar mass. We consider beyond-$\Lambda$CDM power-spectrum enhancements and show that any departure large enough to reproduce the abundance of ultra-massive JWST candidates is in conflict with the HST data. Our analysis, therefore, severely disfavors a cosmological explanation for the JWST abundance problem. Looking ahead, we determine the maximum allowable stellar-mass function and provide projections for the high-$z$ UV LF given our constraints on cosmology from current HST data.

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N. Sabti, J. Muñoz and M. Kamionkowski
Mon, 15 May 23
22/53

Comments: 9 pages, 4 figures

Partition function approach to non-Gaussian likelihoods: physically motivated convergence criteria for Markov-chains [CEA]

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http://arxiv.org/abs/2305.07061


Non-Gaussian distributions in cosmology are commonly evaluated with Monte Carlo Markov-chain methods, as the Fisher-matrix formalism is restricted to the Gaussian case. The Metropolis-Hastings algorithm will provide samples from the posterior distribution after a burn-in period, and the corresponding convergence is usually quantified with the Gelman-Rubin criterion. In this paper, we investigate the convergence of the Metropolis-Hastings algorithm by drawing analogies to statistical Hamiltonian systems in thermal equilibrium for which a canonical partition sum exists. Specifically, we quantify virialisation, equipartition and thermalisation of Hamiltonian Monte Carlo Markov-chains for a toy-model and for the likelihood evaluation for a simple dark energy model constructed from supernova data. We follow the convergence of these criteria to the values expected in thermal equilibrium, in comparison to the Gelman-Rubin criterion. We find that there is a much larger class of physically motivated convergence criteria with clearly defined target values indicating convergence. As a numerical tool, we employ physics-informed neural networks for speeding up the sampling process.

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L. Röver, H. Campe, M. Herzog, et. al.
Mon, 15 May 23
24/53

Comments: 12 pages, 6 figures

Prospects of detecting soft X-ray emission from typical WHIM filaments around massive clusters and the Coma cluster soft excess [HEAP]

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http://arxiv.org/abs/2305.07579


While hot ICM in galaxy clusters makes these objects powerful X-ray sources, the cluster’s outskirts and overdense gaseous filaments might give rise to much fainter sub-keV emission. Cosmological simulations show a prominent “focusing” effect of rich clusters on the space density of the Warm-Hot Intergalactic Medium (WHIM) filaments up to a distance of $\sim 10\,{\rm Mpc}$ ($\sim$ turnaround radius, $r_{ta}$) and beyond. Here, we use Magneticum simulations to characterize their properties in terms of integrated emission measure for a given temperature and overdensity cut and the level of contamination by the more dense gas. We suggest that the annuli $(\sim 0.5-1)\times \,r_{ta}$ around massive clusters might be the most promising sites for the search of the gas with overdensity $\lesssim 50$. We model spectral signatures of the WHIM in the X-ray band and identify two distinct regimes for the gas at temperatures below and above $\sim 10^6\,{\rm K}$. Using this model, we estimate the sensitivity of X-ray telescopes to the WHIM spectral signatures. We found that the WHIM structures are within reach of future high spectral resolution missions, provided that the low-density gas is not extremely metal-poor. We then consider the Coma cluster observed by SRG/eROSITA during the CalPV phase as an example of a nearby massive object. We found that beyond the central $r\sim 40’$ ($\sim 1100\,{\rm kpc}$) circle, where calibration uncertainties preclude clean separation of the extremely bright cluster emission from a possible softer component, the conservative upper limits are about an order of magnitude larger than the levels expected from simulations.

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E. E.Churazov, I. I.I.Khabibullin, K. K.Dolag, et. al.
Mon, 15 May 23
27/53

Comments: Submitted to MNRAS

A morphological analysis of the substructures in radio relics [CEA]

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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

Constraining primordial non-Gaussianity from DESI quasar targets and Planck CMB lensing [CEA]

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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

Mitigating the optical depth degeneracy in the cosmological measurement of neutrino masses using 21-cm observations [CEA]

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http://arxiv.org/abs/2305.07056


Massive neutrinos modify the expansion history of the universe and suppress the structure formation below their free streaming scale. Cosmic microwave background (CMB) observations at small angular scales can be used to constrain the total mass $\Sigma m_\nu$ of the three neutrino flavors. However, at these scales, the CMB-measured $\Sigma m_\nu$ is degenerate with $\tau$, the optical depth to reionization, which quantifies the damping of CMB anisotropies due to the scattering of CMB photons with free electrons along the line of sight. Here we revisit the idea to use 21-cm power spectrum observations to provide direct estimates for $\tau$. A joint analysis of CMB and 21-cm data can alleviate the $\tau-\Sigma m_\nu$ degeneracy, making it possible to measure $\Sigma m_\nu$ with unprecedented precision. Forecasting for the upcoming Hydrogen Epoch of Reionization Array (HERA), we find that a $\lesssim\mathcal{O}(10\%)$ measurement of $\tau$ is achievable, which would enable a $\gtrsim 5\sigma$ measurement of $\Sigma m_\nu=60\,[{\rm meV}]$, for any astrophysics model that we considered. Precise estimates of $\tau$ also help reduce uncertainties in other cosmological parameters, such as $A_s$, the amplitude of the primordial scalar fluctuations power spectrum.

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G. Shmueli, D. Sarkar and E. Kovetz
Mon, 15 May 23
36/53

Comments: 17 pages, 4 figures, 9 tables

Forecasting the power of Higher Order Weak Lensing Statistics with automatically differentiable simulations [IMA]

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http://arxiv.org/abs/2305.07531


We present the Differentiable Lensing Lightcone (DLL), a fully differentiable physical model designed for being used as a forward model in Bayesian inference algorithms requiring access to derivatives of lensing observables with respect to cosmological parameters. We extend the public FlowPM N-body code, a particle-mesh N-body solver, simulating lensing lightcones and implementing the Born approximation in the Tensorflow framework. Furthermore, DLL is aimed at achieving high accuracy with low computational costs. As such, it integrates a novel Hybrid Physical-Neural parameterisation able to compensate for the small-scale approximations resulting from particle-mesh schemes for cosmological N-body simulations. We validate our simulations in an LSST setting against high-resolution $\kappa$TNG simulations by comparing both the lensing angular power spectrum and multiscale peak counts. We demonstrate an ability to recover lensing $C_\ell$ up to a 10% accuracy at $\ell=1000$ for sources at redshift 1, with as few as $\sim 0.6$ particles per Mpc/h. As a first use case, we use this tool to investigate the relative constraining power of the angular power spectrum and peak counts statistic in an LSST setting. Such comparisons are typically very costly as they require a large number of simulations, and do not scale well with the increasing number of cosmological parameters. As opposed to forecasts based on finite differences, these statistics can be analytically differentiated with respect to cosmology, or any systematics included in the simulations at the same computational cost of the forward simulation. We find that the peak counts outperform the power spectrum on the cold dark matter parameter $\Omega_c$, on the amplitude of density fluctuations $\sigma_8$, and on the amplitude of the intrinsic alignment signal $A_{IA}$.

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D. Lanzieri, F. Lanusse, C. Modi, et. al.
Mon, 15 May 23
37/53

Comments: Submitted to A&A, 18 pages, 14 figures, comments are welcome

X-ray surface brightness and gas density profiles of galaxy clusters up to 3*R500c with SRG/eROSITA [CEA]

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http://arxiv.org/abs/2305.07080


Using the data of the SRG/eROSITA all-sky survey, we stacked a sample of ~40 galaxy cluster images in the 0.3–2.3 keV band, covering the radial range up to $10\times R_{\rm 500c}$. The excess emission on top of the galactic and extragalactic X-ray backgrounds and foregrounds is detected up to $\sim 3\times R_{\rm 500c}$. At these distances, the surface brightness of the stacked image drops below $\sim 1$% of the background. The density profile reconstructed from the X-ray surface brightness profile agrees well (within $\sim30$%) with the mean gas profile found in numerical simulations, which predict the local gas overdensity of $\sim$ 20–30 at $3\times R_{\rm 500c}$ and the gas fraction close to the universal value of $\frac{\Omega_b}{\Omega_m}\approx 0.15$ in the standard $\Lambda$CDM model. Taking at face value, this agreement suggests that up to $\sim 3\times R_{\rm 500c}$ the X-ray signal is not strongly boosted by the gas clumpiness, although a scenario with a moderately inhomogeneous gas cannot be excluded. A comparison of the derived gas density profile with the electron pressure profile based on the SZ measurements suggests that by $r\sim 3\times R_{\rm 500c}$ the gas temperature drops by a factor of $\sim$ 4–5 below the characteristic temperature of a typical cluster in the sample within $R_{\rm 500c}$, while the entropy keeps growing up to this distance. Better constraints on the gas properties just beyond $3\times R_{\rm 500c}$ should be possible with a sample larger than used for this pilot study.

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N. Lyskova, E. Churazov, I. Khabibullin, et. al.
Mon, 15 May 23
38/53

Comments: submitted to MNRAS

The nuclear reaction network WinNet [IMA]

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http://arxiv.org/abs/2305.07048


We present the state-of-the-art single-zone nuclear reaction network WinNet that is capable of calculating the nucleosynthetic yields of a large variety of astrophysical environments and conditions. This ranges from the calculation of the primordial nucleosynthesis where only a few nuclei are considered to the ejecta of neutron star mergers with several thousands of involved nuclei. Here we describe the underlying physics and implementation details of the reaction network. We additionally present the numerical implementation of two different integration methods, the implicit Euler method and Gears method along with their advantages and disadvantages. We furthermore describe basic example cases of thermodynamic conditions that we provide together with the network and demonstrate the reliability of the code by using simple test cases. Once the manuscript has been accepted for publication, WinNet will be publicly available and open source.

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M. Reichert, C. Winteler, O. Korobkin, et. al.
Mon, 15 May 23
44/53

Comments: N/A