Category Archives: Cosmology and Extragalactic Astrophysics

Stochastic gravitational wave background constraints from Gaia DR3 astrometry [CEA]

Posted on by

http://arxiv.org/abs/2304.06350


Astrometric surveys can be used to constrain the stochastic gravitational wave background (SGWB) at very low frequencies. We use proper motion data provided by Gaia DR3 to fit a generic dipole+quadrupole field. We analyse several quasar-based datasets and discuss their purity and idoneity to set constraints on gravitational waves. For the cleanest dataset, we derive an upper bound on the (frequency-integrated) energy density of the SGWB $h_{70}^2\Omega_{\rm GW}\lesssim 0.087$ for $4.2\times 10^{-18}~\mathrm{Hz}\lesssim f\lesssim 1.1\times 10^{-8}~\mathrm{Hz}$. We also reanalyse previous VLBI-based data to set the constraint $h_{70}^2\Omega_{\rm GW}\lesssim 0.024$ for $5.8\times 10^{-18}~\mathrm{Hz}\lesssim f\lesssim 1.4\times 10^{-9}~\mathrm{Hz}$ under the same formalism, standing as the best astrometric constraint on GWs. Based on our results, we discuss the potential of future Gaia data releases to impose tighter constraints.

Read this paper on arXiv…

S. Jaraba, J. García-Bellido, S. Kuroyanagi, et. al.
Fri, 14 Apr 23
24/64

Comments: 15 pages, 7 figures

Revisiting Friedmann-like cosmology with torsion: newest constraints from high-redshift observations [CEA]

Posted on by

http://arxiv.org/abs/2304.06425


As one of the possible extensions of Einstein’s General Theory of Relativity, it has been recently suggested that the presence of spacetime torsion could solve problems of the very early and the late-time universe undergoing accelerating phases. In this paper, we use the latest observations of high-redshift data, coming from multiple measurements of quasars and baryon acoustic oscillations, to phenomenologically constrain such cosmological model in the framework of Einstein-Cartan (EC) endowed with spacetime torsion. Such newly compiled quasar datasets in the cosmological analysis is crucial to this aim, since it will extend the Hubble diagram to high-redshift range in which predictions from different cosmologies can be distinguished. Our results show that out of all the candidate models, the torsion plus cosmological constant model is strongly favoured by the current high-redshift data, where torsion itself would be expected to yield the current cosmic acceleration. Specially, in the framework of Friedmann-like cosmology with torsion, the determined Hubble constant is in very good agreement with that derived from the Planck 2018 CMB results. On the other hand, our results are compatible with zero spatial curvature and there is no significant deviation from flat spatial hypersurfaces. Finally, we check the robustness of high-redshift observations by placing constraints on the torsion parameter $\alpha$, which is strongly consistent with other recent works focusing on torsion effect on the primordial helium-4 abundance.

Read this paper on arXiv…

T. Liu, Z. Liu, J. Wang, et. al.
Fri, 14 Apr 23
28/64

Comments: 23 pages, 5 figures

Universal Gravitational Wave Signatures of Cosmological Solitons [CEA]

Posted on by

http://arxiv.org/abs/2304.06709


Cosmological solitonic objects such as monopoles, cosmic strings, domain walls, oscillons and Q-balls often appear in theories of the early Universe. We demonstrate that such scenarios are generically accompanied by a novel production source of gravitational waves stemming from soliton isocurvature perturbations. The resulting induced universal gravitational waves (UGWs) reside at lower frequencies compared to gravitational waves typically associated with soliton formation. We show that UGWs from axion-like particle (ALP) oscillons, originating from ALP misalignment, extend the frequency range of produced gravitational waves by more than two orders of magnitude regardless of the ALP mass and decay constant and can be observable in upcoming gravitational wave experiments. UGWs open a new route for gravitational wave signatures in broad classes of cosmological theories.

Read this paper on arXiv…

K. Lozanov, M. Sasaki and V. Takhistov
Fri, 14 Apr 23
29/64

Comments: 8 pages, 2 figures

A new marked correlation function scheme for testing gravity [CEA]

Posted on by

http://arxiv.org/abs/2304.06218


We introduce a new scheme based on the marked correlation function to probe gravity using the large-scale structure of the Universe. We illustrate our approach by applying it to simulations of the metric-variation $f(R)$ modified gravity theory and general relativity (GR). The modifications to the equations in $f(R)$ gravity lead to changes in the environment of large-scale structures that could, in principle, be used to distinguish this model from GR. Applying the Monte Carlo Markov Chain algorithm, we use the observed number density and two-point clustering to fix the halo occupation distribution (HOD) model parameters and build mock galaxy catalogues from both simulations. To generate a mark for galaxies when computing the marked correlation function we estimate the local density using a Voronoi tessellation. Our approach allows us to isolate the contribution to the uncertainty in the predicted marked correlation function that arises from the range of viable HOD model parameters, in addition to the sample variance error for a single set of HOD parameters. This is critical for assessing the discriminatory power of the method. In a companion paper we apply our new scheme to a current large-scale structure survey.

Read this paper on arXiv…

J. Armijo, C. Baugh, P. Norberg, et. al.
Fri, 14 Apr 23
32/64

Comments: 11 pages, 7 figures

Cosmology with one galaxy? — The ASTRID model and robustness [CEA]

Posted on by

http://arxiv.org/abs/2304.06084


Recent work has pointed out the potential existence of a tight relation between the cosmological parameter $\Omega_{\rm m}$, at fixed $\Omega_{\rm b}$, and the properties of individual galaxies in state-of-the-art cosmological hydrodynamic simulations. In this paper, we investigate whether such a relation also holds for galaxies from simulations run with a different code that made use of a distinct subgrid physics: Astrid. We find that also in this case, neural networks are able to infer the value of $\Omega_{\rm m}$ with a $\sim10\%$ precision from the properties of individual galaxies while accounting for astrophysics uncertainties as modeled in CAMELS. This tight relationship is present at all considered redshifts, $z\leq3$, and the stellar mass, the stellar metallicity, and the maximum circular velocity are among the most important galaxy properties behind the relation. In order to use this method with real galaxies, one needs to quantify its robustness: the accuracy of the model when tested on galaxies generated by codes different from the one used for training. We quantify the robustness of the models by testing them on galaxies from four different codes: IllustrisTNG, SIMBA, Astrid, and Magneticum. We show that the models perform well on a large fraction of the galaxies, but fail dramatically on a small fraction of them. Removing these outliers significantly improves the accuracy of the models across simulation codes.

Read this paper on arXiv…

N. Echeverri, F. Villaescusa-Navarro, C. Chawak, et. al.
Fri, 14 Apr 23
34/64

Comments: 16 pages, 12 figures

Exploring Mirror Twin Higgs Cosmology with Present and Future Weak Lensing Surveys [CEA]

Posted on by

http://arxiv.org/abs/2304.06308


We explore the potential of precision cosmological data to study non-minimal dark sectors by updating the cosmological constraint on the mirror twin Higgs model (MTH). The MTH model addresses the Higgs little hierarchy problem by introducing dark sector particles. In this work, we perform a Bayesian global analysis that includes the latest cosmic shear measurement from the DES three-year survey and the Planck CMB and BAO data. In the early Universe, the mirror baryon and mirror radiation behave as dark matter and dark radiation, and their presence modifies the Universe’s expansion history. Additionally, the scattering between mirror baryon and photon generates the dark acoustic oscillation process, suppressing the matter power spectrum from the cosmic shear measurement. We demonstrate how current data constrain these corrections to the $\Lambda$CDM cosmology and find that for a viable solution to the little hierarchy problem, the proportion of MTH dark matter cannot exceed about $30\%$ of the total dark matter density, unless the temperature of twin photon is less than $30\%$ of that of the standard model photon. While the MTH model is presently not a superior solution to the observed $H_0$ tension compared to the $\Lambda$CDM+$\Delta N_{\rm eff}$ model, we demonstrate that it has the potential to alleviate both the $H_0$ and $S_8$ tensions, especially if the $S_8$ tension persists in the future and approaches the result reported by the Planck SZ (2013) analysis. In this case, the MTH model can relax the tensions while satisfying the DES power spectrum constraint up to $k \lesssim 10~h\rm {Mpc}^{-1}$. If the MTH model is indeed accountable for the $S_8$ and $H_0$ tensions, we show that the future China Space Station Telescope (CSST) can determine the twin baryon abundance with a $10\%$ level precision.

Read this paper on arXiv…

L. Zu, C. Zhang, H. Chen, et. al.
Fri, 14 Apr 23
48/64

Comments: 32 pages, 12 figures, 4 tables

Addressing the self-interaction for ELDER dark matter from the 21-cm signal [CEA]

Posted on by

http://arxiv.org/abs/2304.06680


The self-interacting dark matter can affect various cosmological processes. Such interactions can be number conserving (\emph{e.g.} $2 \rightarrow 2$) or number violating (\emph{e.g.} $3 \rightarrow 2,\,4 \rightarrow 2$ etc.). The latter processes where three (or more) dark matter particles undergo self-annihilation/scattering to produce less number of dark matter is termed as “Cannibalism” process. In this work, the self-interaction of dark matter and the strength of such interactions are investigated in the light of experimental results of the global 21-cm spectrum of neural hydrogen from the era of cosmic dawn. From the present work, it appears that $2\rightarrow 2$ process is much more dominant over the $3\rightarrow 2$ process. It is also found that such interactions affect the dark matter-baryon elastic scattering cross-section. The study also indicates the presence of multi component dark matter of different mass range in the Universe.

Read this paper on arXiv…

R. Basu, D. Majumdar, A. Halder, et. al.
Fri, 14 Apr 23
49/64

Comments: 19 pages, 5 figures

Cosmological application of the lens-redshift probability distribution with improved galaxy-scale gravitational lensing sample [CEA]

Posted on by

http://arxiv.org/abs/2304.06529


We conduct the cosmological analysis by using the lens-redshift distribution test with updated galaxy-scale strong lensing sample, where the considered scenarios involve three typical cosmological models (i.e., $\Lambda$CDM, $\omega$CDM and $\omega_0\omega_a$CDM models) and three typical choices (i.e., non-evolving, power-law and exponential forms) for the velocity-dispersion distribution function (VDF) of lens galaxies. It shows that degeneracies between cosmological and VDF parameters lead to the shifts of estimates on the parameters. The limits on $\Omega_{m0}$ from the lens-redshift distribution are consistent with those from the Pantheon+ Type Ia supernova (SN Ia) sample at 68.3% confidence level, though the uncertainties on $\Omega_{m0}$ from the former are about 3 to 8 times larger than those from the latter. The mean values of $\Omega_{m0}$ shift to the larger values in the power-law VDF case and to the lower values in the exponential VDF case, compared with those obtained in the non-evolving VDF case. In the $\omega$CDM model, the limits on $\omega_0$, i.e. the dark energy equation of state (EoS), are consistent with those from the Pantheon+ sample at 68.3% confidence level, but the mean values of $\omega_0$ from the former are significantly smaller than those from the latter. In the $\omega_0\omega_a$CDM model, the uncertainties on $\omega_0$ are dramatically enlarged compared with those obtained in the $\omega$CDM model; moreover, the Markov chains of $\omega_a$, i.e. the time-varying slope of EoS, do not achieve convergence in the three VDF cases. Overall, the lens-redshift distribution test is more effective on constraining $\Omega_{m0}$ than on the dark energy EoS.

Read this paper on arXiv…

H. Li and Y. Chen
Fri, 14 Apr 23
60/64

Comments: 10 pages, 3 figures, 1 table

Impact of dark matter spikes on the merger rates of Primordial Black Holes [CEA]

Posted on by

http://arxiv.org/abs/2304.05892


Mergers of Primordial Black Holes (PBHs) may contribute to the gravitational wave mergers detected by the LIGO-Virgo-KAGRA (LVK) Collaboration. We study the dynamics of PBH binaries dressed with dark matter (DM) spikes, for PBHs with extended mass functions. We analyze the impact of DM spikes on the orbital parameters of the PBH binaries formed in the early Universe and calculate their merger rates at the age of the Universe today. We consider two possible scenarios for the dynamics of the dressed binaries: assuming that either the DM spikes are completely evaporated from the binaries before merger or they remain static until the merger. Contrary to previous studies, we find that the presence of spikes may increase or decrease the present-day PBH merger rates, in some cases dramatically. Comparing with merger rates reported by the LVK Collaboration in the third Gravitational Wave Transient Catalog (GWTC-3), we derive approximate constraints on the fraction of Solar-mass PBHs in cold dark matter as $f_\mathrm{pbh}\leq \mathcal{O}(10^{-5} – 10^{-3})$, depending on the mass function. Our calculations are valid only for the idealized scenarios in which the DM spikes are either evaporated or static. However, they suggest that the impact of DM spikes on PBH merger rates may be more complicated than previously thought and motivate the development of a more general description of the merger dynamics, including feedback of the DM spikes in highly eccentric PBH binaries.

Read this paper on arXiv…

P. Jangra, B. Kavanagh and J. Diego
Thu, 13 Apr 23
6/59

Comments: 29 pages, 12 figures + 2 appendices

Cosmological constraints from standardized non-CMB observations [CEA]

Posted on by

http://arxiv.org/abs/2304.05522


The current expansion of the Universe has been observed to be accelerating, and the widely accepted spatially-flat concordance model of general relativistic cosmology attributes this phenomenon to a constant dark energy, a cosmological constant, which is measured to comprise about 70% of the total energy budget of the current Universe. However, observational discrepancies and theoretical puzzles have raised questions about this model, suggesting that alternative cosmological models with non-zero spatial curvature and/or dark energy dynamics might provide better explanations.
To explore these possibilities, we have conducted a series of studies using standardized, lower-redshift observations to constrain six different cosmological models with varying degrees of flatness and dark energy dynamics. Through comparing these observations with theoretical predictions, we aim to deepen our understanding of the evolution of the Universe and shed new light on its mysteries. Our data provide consistent cosmological constraints across all six models, with some suggesting the possibility of mild dark energy dynamics and slight spatial curvature. However, these joint constraints do not rule out the possibility of dark energy being a cosmological constant and the spatial hypersurfaces being flat. Overall, our findings contribute to the ongoing efforts to refine our understanding of the Universe and its properties, and suggest that multiple cosmological models remain viable.

Read this paper on arXiv…

S. Cao
Thu, 13 Apr 23
10/59

Comments: Ph.D. thesis, Kansas State University

Lensing with generalized symmetrons [CEA]

Posted on by

http://arxiv.org/abs/2304.05875


Generalized symmetrons are models that have qualitatively similar features to the archetypal symmetron, but have barely been studied. In this article, we investigate for what parameter values the fifth forces induced by disformally coupling generalized symmetrons can provide an explanation for the difference between baryonic and lens masses of galaxies. While it is known that the standard symmetron struggles with providing an alternative source for the lensing otherwise attributed to particle dark matter, we show that some generalized symmetron models are more suitable for complying with existing constraints on disformal couplings. This motivates future studies of these only little explored models.

Read this paper on arXiv…

C. Käding
Thu, 13 Apr 23
11/59

Comments: 18 pages, 4 figures

Cosmological constraints from HSC Y1 lensing convergence PDF [CEA]

Posted on by

http://arxiv.org/abs/2304.05928


We utilize the probability distribution function (PDF) of convergence maps reconstructed from the Subaru Hyper Suprime-Cam (HSC) Y1 shear catalogue, in combination with the power spectrum, to measure the matter clustering amplitude $S_8=\sigma_8\sqrt{\Omega_m/0.3}$. The large-scale structure’s statistical properties are incompletely described by the traditional two-point statistics, motivating our investigation of the PDF — a complementary higher-order statistic. By defining the PDF over the standard deviation-normalized convergence map we are able to isolate the non-Gaussian information. We use tailored simulations to compress the data vector and construct a likelihood approximation. We mitigate the impact of survey and astrophysical systematics with cuts on smoothing scales, redshift bins, and data vectors. We find $S_8=0.852^{+0.086}{-0.094}$ from the PDF alone and $S_8=0.827^{+0.033}{-0.044}$ from the combination of PDF and power spectrum (68% CL). The PDF improves the power spectrum-only constraint by about 10%.

Read this paper on arXiv…

L. Thiele, G. Marques, J. Liu, et. al.
Thu, 13 Apr 23
26/59

Comments: 6 pages, 4 figures

Analysis of the impact of broad absorption lines on quasar redshift measurements with synthetic observations [CEA]

Posted on by

http://arxiv.org/abs/2304.05855


Accurate quasar classifications and redshift measurements are increasingly important to precision cosmology experiments. Broad absorption line (BAL) features are present in 15-20\% of all quasars, and these features can introduce systematic redshift errors, and in extreme cases produce misclassifications. We quantitatively investigate the impact of BAL features on quasar classifications and redshift measurements with synthetic spectra that were designed to match observations by the Dark Energy Spectroscopic Instrument (DESI) survey. Over the course of five years, DESI aims to measure spectra for 40 million galaxies and quasars, including nearly three million quasars. Our synthetic quasar spectra match the signal-to-noise ratio and redshift distributions of the first year of DESI observations, and include the same synthetic quasar spectra both with and without BAL features. We demonstrate that masking the locations of the BAL features decreases the redshift errors by about 1\% and reduces the number of catastrophic redshift errors by about 80\%. We conclude that identifying and masking BAL troughs should be a standard part of the redshift determination step for DESI and other large-scale spectroscopic surveys of quasars.

Read this paper on arXiv…

L. García, P. Martini, A. Gonzalez-Morales, et. al.
Thu, 13 Apr 23
27/59

Comments: 12 pages, 9 figures, submitted to MNRAS

Cosmic Strings from Thermal Inflation [CEA]

Posted on by

http://arxiv.org/abs/2304.05666


Thermal inflation was proposed as a mechanism to dilute the density of cosmological moduli. Thermal inflation is driven by a complex scalar field possessing a large vacuum expectation value and a very flat potential, called a `flaton’. Such a model admits cosmic string solutions, and a network of such strings will inevitably form in the symmetry breaking phase transition at the end of the period of thermal inflation. We discuss the differences of these strings compared to the strings which form in the Abelian Higgs model. Specifically, we find that the upper bound on the symmetry breaking scale is parametrically lower than in the case of Abelian Higgs strings, and that the lower cutoff on the string loop distribution is determined by cusp annihilation rather than by gravitational radiation (for the value of the transition temperature proposed in the original work on thermal inflation).

Read this paper on arXiv…

R. Brandenberger and A. Favero
Thu, 13 Apr 23
31/59

Comments: 6 pages

The thermal history of the intergalactic medium at $3.9 \leq z \leq 4.3$ [CEA]

Posted on by

http://arxiv.org/abs/2304.05519


A new determination of the temperature of the intergalactic medium over $3.9 \leq z \leq 4.3$ is presented. We applied the curvature method on a sample of 10 high resolution quasar spectra from the Ultraviolet and Visual Echelle Spectrograph on the VLT/ESO. We measured the temperature at mean density by determining the temperature at the characteristic overdensity, which is tight function of the absolute curvature irrespective of $\gamma$. Under the assumption of fiducial value of $\gamma = 1.4$, we determined the values of temperatures at mean density $T_{0} = 7893^{+1417}{-1226}$ K and $T{0} = 8153^{+1224}_{-993}$ K for redshift range of $3.9 \leq z \leq 4.1$ and $4.1 \leq z \leq 4.3$, respectively. Even though the results show no strong temperature evolution over the studied redshift range, our measurements are consistent with an intergalactic medium thermal history that includes a contribution from He II reionization.

Read this paper on arXiv…

T. Ondro and R. Gális
Thu, 13 Apr 23
44/59

Comments: Accepted for publication in PASA, 9 pages, 8 figures

Indirect imprints of primordial non-Gaussianity on cosmic microwave background [CEA]

Posted on by

http://arxiv.org/abs/2304.05941


Primordial non-Gaussianity arising from inflationary models is a unique probe of non-trivial dynamics of the inflaton field and its interactions with other fields. Often when examining and constraining the scalar non-Gaussianity arising from inflation, certain templates are adopted for the scalar non-Gaussianity parameter $f_{{\rm NL}}$, in classifying their behaviors in terms of wavenumbers. The current constraints from cosmic microwave background (CMB) on such templates of $f{{\rm NL}}$ are weak and provide rather large bounds on their amplitudes. In this work, we explore a different method of constraining $f{{\rm NL}}$ through their effect on the scalar power. We compute the correction to the scalar power due to $f{{\rm NL}}$ while accounting for its generic scale dependence. We then compute the angular power spectrum of CMB arising from such non-Gaussian corrections to explore possible imprints. We initially illustrate this method using the conventional templates of $f{{\rm NL}}$ such as local, equilateral and orthogonal types, with and without the running of the parameter. We further employ this method to an oscillatory form of $f{{\rm NL}}$ and lastly on a realistic model of inflation proposed by Starobinsky. Though this method does not improve much on the constraints on the first three templates of $f{{\rm NL}}$, it provides interesting insights on models that do not conform to these templates. We infer that the non-Gaussian correction to the spectrum can be sensitive to model parameters that are degenerate at the level of the original power spectrum. Hence, this method of computing indirect imprints of $f{_{\rm NL}}$ on angular power spectrum of CMB provides a new avenue to explore primordial scalar non-Gaussianity and possibly constrain them effectively.

Read this paper on arXiv…

B. Das and H. Ragavendra
Thu, 13 Apr 23
53/59

Comments: 24 pages, 16 figures

Monomial warm inflation revisited [CEA]

Posted on by

http://arxiv.org/abs/2304.05978


We revisit the idea that the inflaton may have dissipated part of its energy into a thermal bath during inflation, considering monomial inflationary potentials and three different forms of dissipation rate. Using a numerical Fokker-Planck approach to describe the stochastic dynamics of inflationary fluctuations, we confront this scenario with current bounds on the spectrum of curvature fluctuations and primordial gravitational waves. We also obtain analytical approximations that outperform those frequently used in previous analyses. We show that only our numerical Fokker-Planck method is accurate, fast and precise enough to test these models against current data. We advocate its use in future studies of warm inflation. We also apply the stochastic inflation formalism to this scenario, finding that a commonly implemented large thermal correction to the primordial spectrum–that had been argued to become apparent with it–is actually not required. Improved bounds on the scalar spectral index will further constrain warm inflation in the near future.

Read this paper on arXiv…

G. Ballesteros, A. Rodríguez and M. Pierre
Thu, 13 Apr 23
55/59

Comments: 55 pages, 12 figures

The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and its Implications for Structure Growth [CEA]

Posted on by

http://arxiv.org/abs/2304.05202


We present new measurements of cosmic microwave background (CMB) lensing over $9400$ sq. deg. of the sky. These lensing measurements are derived from the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB dataset, which consists of five seasons of ACT CMB temperature and polarization observations. We determine the amplitude of the CMB lensing power spectrum at $2.3\%$ precision ($43\sigma$ significance) using a novel pipeline that minimizes sensitivity to foregrounds and to noise properties. To ensure our results are robust, we analyze an extensive set of null tests, consistency tests, and systematic error estimates and employ a blinded analysis framework. The baseline spectrum is well fit by a lensing amplitude of $A_{\mathrm{lens}}=1.013\pm0.023$ relative to the Planck 2018 CMB power spectra best-fit $\Lambda$CDM model and $A_{\mathrm{lens}}=1.005\pm0.023$ relative to the $\text{ACT DR4} + \text{WMAP}$ best-fit model. From our lensing power spectrum measurement, we derive constraints on the parameter combination $S^{\mathrm{CMBL}}_8 \equiv \sigma_8 \left({\Omega_m}/{0.3}\right)^{0.25}$ of $S^{\mathrm{CMBL}}_8= 0.818\pm0.022$ from ACT DR6 CMB lensing alone and $S^{\mathrm{CMBL}}_8= 0.813\pm0.018$ when combining ACT DR6 and Planck NPIPE CMB lensing power spectra. These results are in excellent agreement with $\Lambda$CDM model constraints from Planck or $\text{ACT DR4} + \text{WMAP}$ CMB power spectrum measurements. Our lensing measurements from redshifts $z\sim0.5$–$5$ are thus fully consistent with $\Lambda$CDM structure growth predictions based on CMB anisotropies probing primarily $z\sim1100$. We find no evidence for a suppression of the amplitude of cosmic structure at low redshifts

Read this paper on arXiv…

F. Qu, B. Sherwin, M. Madhavacheril, et. al.
Wed, 12 Apr 23
4/45

Comments: 45+21 pages, 50 figures. Prepared for submission to ApJ. Also see companion papers Madhavacheril et al and MacCrann et al

Field-level inference of cosmic shear with intrinsic alignments and baryons [CEA]

Posted on by

http://arxiv.org/abs/2304.04785


We construct a field-based Bayesian Hierarchical Model for cosmic shear that includes, for the first time, the important astrophysical systematics of intrinsic alignments and baryon feedback, in addition to a gravity model. We add to the BORG-WL framework the tidal alignment and tidal torquing model (TATT) for intrinsic alignments and compare them with the non-linear alignment (NLA) model. With synthetic data, we have shown that adding intrinsic alignments and sampling the TATT parameters does not reduce the constraining power of the method and the field-based approach lifts the weak lensing degeneracy. We add baryon effects at the field level using the enthalpy gradient descent (EGD) model. This model displaces the dark matter particles without knowing whether they belong to a halo and allows for self-calibration of the model parameters, which are inferred from the data. We have also illustrated the effects of model misspecification for the baryons. The resulting model now contains the most important physical effects and is suitable for application to data.

Read this paper on arXiv…

N. Porqueres, A. Heavens, D. Mortlock, et. al.
Wed, 12 Apr 23
10/45

Comments: N/A

Reionizing islands with inhomogeneous recombinations [CEA]

Posted on by

http://arxiv.org/abs/2304.05050


Observations are beginning to constrain the history of the epoch of reionization (EoR). Modeling the reionization process is indispensable to interpret the observations, to infer the properties of ionizing sources, and to probe the various astrophysical processes from the observational data. Here we present an improved version of the semi-numerical simulation islandFAST, by incorporating inhomogeneous recombinations and a corresponding inhomogeneous ionizing background, and simulate the reionization process of neutral islands during the late EoR. We find that the islands are more fragmented in models with inhomogeneous recombinations than the case with a homogeneous recombination number. In order to investigate the effects of basic assumptions in the reionization modeling, we compare the results from islandFAST with those from 21cmFAST for the same assumptions on the ionizing photon sources and sinks, to find how the morphology of the ionization field and the reionization history depend on the different treatments of these two models. Such systematic bias should be noted when interpreting the upcoming observations.

Read this paper on arXiv…

R. Zhu, Y. Xu, B. Yue, et. al.
Wed, 12 Apr 23
11/45

Comments: 19 pages, 10 figures. Accepted for publication in Research in Astronomy and Astrophysics

Aether Scalar Tensor (AeST) theory: Quasistatic spherical solutions and their phenomenology [CEA]

Posted on by

http://arxiv.org/abs/2304.05134


There have been many efforts in the last three decades to embed the empirical MOND program into a robust theoretical framework. While many such theories can explain the profile of galactic rotation curves, they usually cannot explain the evolution 15 the primordial fluctuations and the formation of large-scale-structures in the Universe. The Aether Scalar Tensor (AeST) theory seems to have overcome this difficulty, thereby providing the first compelling example of an extension of general relativity able to successfully challenge the particle dark matter hypothesis. Here we study the phenomenology of this theory in the quasistatic weak-field regime and specifically for the idealised case of spherical isolated sources.
We find the existence of three distinct gravitational regimes, that is, Newtonian, MOND and a third regime characterised by the presence of oscillations in the gravitational potential which do not exist in the traditional MOND paradigm. We identify the transition scales between these three regimes and discuss their dependence on the boundary conditions and other parameters in the theory. Aided by analytical and numerical solutions, we explore the dependence of these solutions on the theory parameters. Our results could help in searching for interesting observable phenomena at low redshift pertaining to galaxy dynamics as well as lensing observations, however, this may warrant proper N-body simulations that go beyond the idealised case of spherical isolated sources.

Read this paper on arXiv…

P. Verwayen, C. Skordis and C. Bœhm
Wed, 12 Apr 23
34/45

Comments: 15 pages, 8 figures

Benchmarks of Dark Energy [CEA]

Posted on by

http://arxiv.org/abs/2304.04803


Dark energy is a premier mystery of physics, both theoretical and experimental. As we look to develop plans for high energy physics over the next decade, within a two decade view, we consider benchmarks for revealing the nature of dark energy. We conclude, based on fundamental physical principles detailed below, that understanding will come from experiments reaching key benchmarks:
$\bullet\ \sigma(w_a)<2.5\sigma(w_0)$
$\bullet\ \sigma(w_0)<0.02$
$ \bullet\ \sigma(\rho_{\rm de}/\rho_{\rm crit})<(1/3)\rho_\Lambda/\rho_{\rm crit}$ for all redshifts $z<5$
where the dark energy equation of state $w(a)=w_0+w_a(1-a)$. Beyond the cosmic expansion history we also discuss benchmarks for the cosmic growth history appropriate for testing classes of gravity theories. All benchmarks can be achieved by a robust Stage 5 program, using extensions of existing probes plus the highly complementary, novel probe of cosmic redshift drift.

Read this paper on arXiv…

E. Linder
Wed, 12 Apr 23
36/45

Comments: 7 pages

The Atacama Cosmology Telescope: Mitigating the impact of extragalactic foregrounds for the DR6 CMB lensing analysis [CEA]

Posted on by

http://arxiv.org/abs/2304.05196


We investigate the impact and mitigation of extragalactic foregrounds for the CMB lensing power spectrum analysis of Atacama Cosmology Telescope (ACT) data release 6 (DR6) data. Two independent microwave sky simulations are used to test a range of mitigation strategies. We demonstrate that finding and then subtracting point sources, finding and then subtracting models of clusters, and using a profile bias-hardened lensing estimator, together reduce the fractional biases to well below statistical uncertainties, with the inferred lensing amplitude, $A_{\mathrm{lens}}$, biased by less than $0.2\sigma$. We also show that another method where a model for the cosmic infrared background (CIB) contribution is deprojected and high frequency data from Planck is included has similar performance. Other frequency-cleaned options do not perform as well, incurring either a large noise cost, or resulting in biased recovery of the lensing spectrum. In addition to these simulation-based tests, we also present null tests performed on the ACT DR6 data which test for sensitivity of our lensing spectrum estimation to differences in foreground levels between the two ACT frequencies used, while nulling the CMB lensing signal. These tests pass whether the nulling is performed at the map or bandpower level. The CIB-deprojected measurement performed on the DR6 data is consistent with our baseline measurement, implying contamination from the CIB is unlikely to significantly bias the DR6 lensing spectrum. This collection of tests gives confidence that the ACT DR6 lensing measurements and cosmological constraints presented in companion papers to this work are robust to extragalactic foregrounds.

Read this paper on arXiv…

N. MacCrann, B. Sherwin, F. Qu, et. al.
Wed, 12 Apr 23
38/45

Comments: Companion paper to Qu et al and Madhavacheril et al

The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters [CEA]

Posted on by

http://arxiv.org/abs/2304.05203


We present cosmological constraints from a gravitational lensing mass map covering 9400 sq. deg. reconstructed from CMB measurements made by the Atacama Cosmology Telescope (ACT) from 2017 to 2021. In combination with BAO measurements (from SDSS and 6dF), we obtain the amplitude of matter fluctuations $\sigma_8 = 0.819 \pm 0.015$ at 1.8% precision, $S_8\equiv\sigma_8({\Omega_{\rm m}}/0.3)^{0.5}=0.840\pm0.028$ and the Hubble constant $H_0= (68.3 \pm 1.1)\, \text{km}\,\text{s}^{-1}\,\text{Mpc}^{-1}$ at 1.6% precision. A joint constraint with CMB lensing measured by the Planck satellite yields even more precise values: $\sigma_8 = 0.812 \pm 0.013$, $S_8\equiv\sigma_8({\Omega_{\rm m}}/0.3)^{0.5}=0.831\pm0.023$ and $H_0= (68.1 \pm 1.0)\, \text{km}\,\text{s}^{-1}\,\text{Mpc}^{-1}$. These measurements agree well with $\Lambda$CDM-model extrapolations from the CMB anisotropies measured by Planck. To compare these constraints to those from the KiDS, DES, and HSC galaxy surveys, we revisit those data sets with a uniform set of assumptions, and find $S_8$ from all three surveys are lower than that from ACT+Planck lensing by varying levels ranging from 1.7-2.1$\sigma$. These results motivate further measurements and comparison, not just between the CMB anisotropies and galaxy lensing, but also between CMB lensing probing $z\sim 0.5-5$ on mostly-linear scales and galaxy lensing at $z\sim 0.5$ on smaller scales. We combine our CMB lensing measurements with CMB anisotropies to constrain extensions of $\Lambda$CDM, limiting the sum of the neutrino masses to $\sum m_{\nu} < 0.12$ eV (95% c.l.), for example. Our results provide independent confirmation that the universe is spatially flat, conforms with general relativity, and is described remarkably well by the $\Lambda$CDM model, while paving a promising path for neutrino physics with gravitational lensing from upcoming ground-based CMB surveys.

Read this paper on arXiv…

M. Madhavacheril, F. Qu, B. Sherwin, et. al.
Wed, 12 Apr 23
42/45

Comments: 30 pages, 16 figures, prepared for submission to ApJ. Cosmological likelihood data is here: this https URL ; likelihood software is here: this https URL . Also see companion papers Qu et al and MacCrann et al. Mass maps will be released when papers are published

CSST forecast: impact from non-Gaussian covariances and requirements on systematics-control [CEA]

Posted on by

http://arxiv.org/abs/2304.04489


The precise estimation of the statistical errors and accurate removal of the systematical errors are the two major challenges for the stage IV cosmic shear surveys. We explore their impact for the China Space-Station Telescope (CSST) with survey area $\sim17,500\deg^2$ up to redshift $\sim4$. We consider statistical error contributed from Gaussian covariance, connected non-Gaussian covariance and super-sample covariance. We find the super-sample covariance can largely reduce the signal-to-noise of the two-point statistics for CSST, leading to a $\sim1/3$ loss in the figure-of-merit for the matter clustering properties ($\sigma_8-\Omega_m$ plane) and $1/6$ in the dark energy equation-of-state ($w_0-w_a$ plane). We further put requirements of systematics-mitigation on: intrinsic alignment of galaxies, baryonic feedback, shear multiplicative bias, and bias in the redshift distribution, for an unbiased cosmology. The $10^{-2}$ to $10^{-3}$ level requirements emphasize strong needs in related studies, to support future model selections and the associated priors for the nuisance parameters.

Read this paper on arXiv…

J. Yao, H. Shan, R. Li, et. al.
Tue, 11 Apr 23
3/63

Comments: submitted to MNRAS

Galileon inflation evades the no-go for PBH formation in the single-field framework [CEA]

Posted on by

http://arxiv.org/abs/2304.04065


We consider Galileon inflation in the Effective Field Theory (EFT) framework and examine the possibility for PBH formation during slow roll (SR) to ultra slow roll (USR) transitions. We show that loop corrections to the power spectrum, in this case, do not impose additional constraints on the masses of PBHs produced. We indicate that the remarkable non-renormalization property of Galileon due to generalized shift symmetry is responsible for protecting PBH formation from quantum loop corrections.

Read this paper on arXiv…

S. Choudhury, S. Panda and M. Sami
Tue, 11 Apr 23
26/63

Comments: 44 pages, 2 figures, Comments are welcome

Kernel Selection for Gaussian Process in Cosmology: with Approximate Bayesian Computation Rejection and Nested Sampling [CEA]

Posted on by

http://arxiv.org/abs/2304.03911


Gaussian Process (GP) has gained much attention in cosmology due to its ability to reconstruct cosmological data in a model-independent manner. In this study, we compare two methods for GP kernel selection: Approximate Bayesian Computation (ABC) Rejection and nested sampling. We analyze three types of data: cosmic Chronometer data (CC), Type Ia Supernovae (SNIa), and Gamma Ray Burst (GRB), using five kernel functions. To evaluate the differences between kernel functions, we assess the strength of evidence using Bayes factors. Our results show that, for ABC Rejection, the Mat\’ern kernel with $\nu$=5/2 (M52 kernel) outperformes the commonly used Radial Basis Function (RBF) kernel in approximating all three datasets. Bayes factors indicate that the M52 kernel typically supports the observed data better than the RBF kernel, but with no clear advantage over other alternatives. However, nested sampling gives different results, with the M52 kernel losing its advantage. Nevertheless, Bayes factors indicate no significant dependence of the data on each kernel.

Read this paper on arXiv…

H. Zhang, Y. Wang, T. Zhang, et. al.
Tue, 11 Apr 23
29/63

Comments: 15 pages, 4 tables, 6 figures, accepted for publication in ApJS. We draw a new conclusion which is different from the standard ABC-related methods(e.g. ABC-SMC) in kernel selection for Gaussian Process

Self-interactions of ULDM to the rescue? [CEA]

Posted on by

http://arxiv.org/abs/2304.04463


One of the most important questions in cosmology is concerning the fundamental nature of dark matter (DM). DM could consist of spinless particles of very small mass i.e. $m \sim 10^{-22}\ \text{eV}$. This kind of ultralight dark matter (ULDM) would form cored density profiles (called “solitons”) at the centre of galaxies. In this context, recently it has been argued that (a) there exists a power law relation between the mass of the soliton and mass of the surrounding halo called the Soliton-Halo (SH) relation, and, (b) the requirement of satisfying observed galactic rotation curves as well as SH relations is so stringent that ULDM is disfavoured from comprising $100\%$ of the total cosmological dark matter. In this work, we revisit these constraints for ULDM particles with non-negligible quartic self-interactions. Using a recently obtained soliton-halo relation which takes into account the effect of self-interactions, we present evidence which suggests that, for $m = 10^{-22}\ \text{eV}$, the requirement of satisfying both galactic rotation curves as well as SH relations can be fulfilled with repulsive self-coupling $\lambda \sim \mathcal{O}(10^{-90})$.

Read this paper on arXiv…

B. Dave and G. Goswami
Tue, 11 Apr 23
58/63

Comments: 26 pages, 8 figures

Posterior Sampling of the Initial Conditions of the Universe from Non-linear Large Scale Structures using Score-Based Generative Models [CEA]

Posted on by

http://arxiv.org/abs/2304.03788


Reconstructing the initial conditions of the universe is a key problem in cosmology. Methods based on simulating the forward evolution of the universe have provided a way to infer initial conditions consistent with present-day observations. However, due to the high complexity of the inference problem, these methods either fail to sample a distribution of possible initial density fields or require significant approximations in the simulation model to be tractable, potentially leading to biased results. In this work, we propose the use of score-based generative models to sample realizations of the early universe given present-day observations. We infer the initial density field of full high-resolution dark matter N-body simulations from the present-day density field and verify the quality of produced samples compared to the ground truth based on summary statistics. The proposed method is capable of providing plausible realizations of the early universe density field from the initial conditions posterior distribution marginalized over cosmological parameters and can sample orders of magnitude faster than current state-of-the-art methods.

Read this paper on arXiv…

R. Legin, M. Ho, P. Lemos, et. al.
Tue, 11 Apr 23
63/63

Comments: 8 pages, 7 figures

The Effect of Boundary Conditions on Structure Formation in Fuzzy Dark Matter [CEA]

Posted on by

http://arxiv.org/abs/2304.03419


We illustrate the effect of boundary conditions on the evolution of structure in Fuzzy Dark Matter. Scenarios explored include the evolution of single, ground-state equilibrium solutions of the Schr\”odinger-Poisson system, the relaxation of a Gaussian density fluctuation, mergers of two equilibrium configurations, and the random merger of many solitons. For comparison, each scenario is evolved twice, with isolation boundary conditions and periodic boundary conditions, the two commonly used to simulate isolated systems and structure formation, respectively. Replacing isolation boundary conditions by periodic boundary conditions changes the domain topology and dynamics of each scenario, by affecting the outcome of gravitational cooling. With periodic boundary conditions, the ground-state equilibrium solution and Gaussian fluctuation each evolve toward the single equilibrium solitonic core of the isolated case, but surrounded by a tail, unlike the isolated versions. The case of head-on, binary mergers illustrates additional effects, caused by the pull suffered by the system due to the infinite network of periodic images along each direction of the domain. Binary merger with angular momentum is the first scenario we found in which the tail has a polynomial profile when using a periodic domain. Finally, the 3D merger of many, randomly-placed solitonic cores of different mass makes a solitonic core surrounded by a tail with power-law-like density profile, for periodic boundary conditions, while producing a core with a much sharper fall-off in the isolated case. This suggests that the conclusion of earlier work that the ground-state equilibrium solution is an attractor for the asymptotic state is true even in 3D and for general circumstances, but only if gravitational cooling is able to carry mass and energy off to infinity, which isolation boundary conditions allow, but periodic ones do not.

Read this paper on arXiv…

I. Alvarez-Ríos, F. Guzmán and P. Shapiro
Mon, 10 Apr 23
2/36

Comments: 17 pages, 18 figures, submitted to Phys. Rev. D

A self-consistent semi-analytic model for Population III star formation in minihalos [CEA]

Posted on by

http://arxiv.org/abs/2304.03358


The formation of the first stars marks a watershed moment in the history of our universe. As the first luminous structures, these stars (also known as Population III, or Pop III stars) seed the first galaxies and begin the process of reionization. We construct an analytic model to self-consistently trace the formation of Pop III stars inside minihalos in the presence of the fluctuating ultraviolet background, relic dark matter-baryon relative velocities from the early universe, and an X-ray background, which largely work to suppress cooling of gas and delay the formation of this first generation of stars. We demonstrate the utility of this framework in a semi-analytic model for early star formation that also follows the transition between Pop III and Pop II star formation inside these halos. Using our new prescription for the criteria allowing Pop III star formation, we follow a population of dark matter halos from $z=50$ through $z=6$ and examine the global star formation history, finding that each process defines its own key epoch: (i) the stream velocity dominates at the highest redshifts ($z\gtrsim30$), (ii) the UV background sets the tone at intermediate times ($30\gtrsim z\gtrsim15$), and (iii) X-rays control the end of Pop III star formation at the latest times ($z\lesssim 15$). In all of our models, Pop III stars continue to form down to $z\sim 7-10$, when their supernovae will be potentially observable with forthcoming instruments. Finally, we identify the signatures of variations in the Pop III physics in the global 21-cm spin-flip signal of atomic hydrogen.

Read this paper on arXiv…

S. Hegde and S. Furlanetto
Mon, 10 Apr 23
24/36

Comments: 19 pages, 14 figures, submitted to MNRAS

Magnetic Fields from Compensated Isocurvature Perturbations [CEA]

Posted on by

http://arxiv.org/abs/2304.03299


Compensated isocurvature perturbations (CIPs) are perturbations to the primordial baryon density that are accompanied by dark-matter-density perturbations so that the total matter density is unperturbed. Such CIPs, which may arise in some multi-field inflationary models, can be long-lived and only weakly constrained by current cosmological measurements. Here we show that the CIP-induced modulation of the electron number density interacts with the electron-temperature fluctuation associated with primordial adiabatic perturbations to produce, via the Biermann-battery mechanism, a magnetic field in the post-recombinaton Universe. This magnetic field may be larger than that (produced at second order in the adiabatic-perturbation amplitude) in the standard cosmological model and may provide seeds for galactic dynamos.

Read this paper on arXiv…

J. Flitter, C. Creque-Sarbinowski, M. Kamionkowski, et. al.
Mon, 10 Apr 23
25/36

Comments: 7 pages, 2 figures

Did the Universe Reheat After Recombination? [CEA]

Posted on by

http://arxiv.org/abs/2304.03750


A key assumption of the standard cosmological model is that the temperature of the cosmic microwave background (CMB) radiation scales with cosmological redshift $z$ as $T_{\rm CMB}(z) \propto (1+z)$ at all times after recombination at $z_\star \simeq 1090$. However, this assumption has only been precisely tested at $z \lesssim 3$. Here, we consider cosmological models with post-recombination reheating (PRR), in which the CMB monopole temperature abruptly increases due to energy injection after last scattering. Such a scenario can potentially resolve tensions between inferences of the current cosmic expansion rate (the Hubble constant, $H_0$). We consider an explicit model in which a metastable sub-component of dark matter (DM) decays to Standard Model photons, whose spectral energy distribution is assumed to be close to that of the CMB blackbody. A fit to Planck CMB anisotropy, COBE/FIRAS CMB monopole, and SH0ES distance-ladder measurements yields $H_0 = 71.2 \pm 1.1$ km/s/Mpc, matter fluctuation amplitude $S_8 = 0.774 \pm 0.018$, and CMB temperature increase $\delta T_{\rm CMB} = 0.109^{+0.033}{-0.044}$ K, which is sourced by DM decay at $z \gtrsim 10$. However, matter density constraints from baryon acoustic oscillation and supernovae data highly constrain this scenario, with a joint fit to all datasets yielding $H_0 = 68.69 \pm 0.35$ km/s/Mpc, $S_8 = 0.8035 \pm 0.0081$, and $\delta T{\rm CMB} < 0.0342$ K (95% CL upper limit). These bounds can be weakened if additional dark relativistic species are present in the early universe, yielding higher $H_0$. We conclude that current data disfavor models with significant PRR solely through its impact on background and linear-theory observables, completely independent of CMB spectral distortion constraints. However, a small amount of such energy injection could play a role in restoring cosmological concordance.

Read this paper on arXiv…

J. Hill and B. Bolliet
Mon, 10 Apr 23
33/36

Comments: 6+8 pages, 1+1 figures

Search for ultra-light axions with CMB polarization [CEA]

Posted on by

http://arxiv.org/abs/2304.03647


When coupled to electromagnetism via a Chern-Simons interaction, axion-like particles (ALP) produce a rotation of the plane of linear polarization of photons known as cosmic birefringence. Recent measurements of cosmic birefringence obtained from the polarization of the cosmic microwave background (CMB) hint at the existence of an isotropic birefringence angle of $\beta\approx 0.3^\circ$, currently excluding $\beta=0$ with a statistical significance of $3.6\sigma$. Were such measurement to be confirmed as a cosmological signal, CMB information alone could constrain the ALP parameter space for masses $m_\phi\lesssim 10^{-27}$eV and axion-photon coupling constants $g_{\phi\gamma}\gtrsim 10^{-20}$GeV$^{-1}$.

Read this paper on arXiv…

P. Diego-Palazuelos
Mon, 10 Apr 23
36/36

Comments: 3 pages, 1 figure. Proceedings of the “The dark matter multi-messenger challenge” Symposia of the 2022 Annual Meeting of the European Astronomical Society. To be published in Memorie della SAIt

Anisotropic Hubble Expansion in Pantheon+ Supernovae [CEA]

Posted on by

http://arxiv.org/abs/2304.02718


We decompose the Pantheon+ Type Ia supernovae (SN) sample in hemispheres on the sky finding angular variations up to $4$ km/s/Mpc in the Hubble constant $H_0$ both in the SH0ES redshift range $0.0233 < z < 0.15$ and in the extended redshift range $0.01 < z < 0.7$. We assume the $\Lambda$CDM model, so our findings become model dependent in extended redshift ranges. $H_0$ is larger in a hemisphere encompassing the CMB dipole direction. The variations we see exceed the errors on the recent SH0ES determination, $H_0 = 73.04 \pm 1.04$ km/s/Mpc, but are not large enough to explain early versus late Universe discrepancies in the Hubble constant. The removal of low redshift SN leads to a weakening of angular $H_0$ variations, but we confirm that they persist beyond the influence of the Shapley supercluster $z > 0.06$

Read this paper on arXiv…

R. McConville and E. Colgáin
Fri, 7 Apr 23
6/50

Comments: 4 pages, 7 figures. Comments welcome

A VLT/VIMOS view of two $Planck$ multiple-cluster systems: structure and galaxy properties [CEA]

Posted on by

http://arxiv.org/abs/2304.03058


We analysed spectroscopic data obtained with VLT-VIMOS for two multiple-cluster systems, PLCKG$214.6+36.9$ and PLCKG$334.8-38.0$, discovered via their thermal Sunyaev-Zel’dovich signal by $Planck$. Combining the Optical spectroscopy, for the redshift determination, and photometric data from galaxy surveys (SDSS, WISE, DESI), we were able to study the structure of the two multiple-cluster systems, to determine their nature and the properties of their member galaxies. We found that the two systems are populated mainly with passive galaxies and that PLCKG$214.6+36.9$ consists of a pair of clusters at redshift $z = 0.445$ and a background isolated cluster at $z = 0.498$, whereas the system PLCKG$334.8-38.0$ is a chance association of three independent clusters at redshifts $z = 0.367$, $z =0.292$, and $z = 0.33$. We also find evidence for remaining star formation activity in the highest-redshift cluster of PLCKG$214.6+36.9$, at $z = 0.498$.

Read this paper on arXiv…

R. Wicker, N. Aghanim, V. Bonjean, et. al.
Fri, 7 Apr 23
11/50

Comments: 12 pages, 9 Figures, 5 Tables. Submitted to A&A, comments are welcome

Minihalos as probes of the inflationary spectrum: accurate boost factor calculation and new CMB constraints [CEA]

Posted on by

http://arxiv.org/abs/2304.02996


Although the spectrum of primordial fluctuations has been accurately measured on scales above $\sim 0.1~\rm{Mpc}$, only upper limits exist on smaller scales. In this study, we investigate generic monochromatic enhancements to the $\Lambda$CDM spectrum that trigger the collapse of ultracompact minihalos (UCMHs) well before standard structure formation. We refine previous treatments by considering a mixed population of halos with different density profiles, that should realistically arise as a consequence of late-time accretion and mergers. Assuming that dark matter (DM) can self-annihilate, we find, as expected, that UCMHs can greatly enhance the annihilation rate around recombination, significantly imprinting the cosmic microwave background (CMB) anisotropies. However, we provide additional insight on the theoretical uncertainties that currently impact that boost and which may affect late-time probes such as the 21 cm line or $\gamma$-ray signals. We derive constraints on the primordial power spectrum on small scales using the ExoCLASS/HYREC codes and the Planck legacy data. We account for the velocity dependence of the DM annihilation cross-section ($s$- or $p$-wave), annihilation channel, the DM particle mass and the inclusion of late-time halo mergers. Our $s$-wave constraints are competitive with previous literature, excluding primordial amplitudes $A_{\star} \gtrsim 10^{-6.5}$ at wavenumbers $k \sim 10^4-10^7 \ \rm{Mpc}^{-1}$. For the first time, we highlight that even $p$-wave processes have constraining power on the primordial spectrum for cross-sections still allowed by currently the strongest astrophysical constraints. Finally, we provide an up-to-date compilation of the most stringent limits on the primordial power spectrum across a wide range of scales.

Read this paper on arXiv…

G. Abellán and G. Facchinetti
Fri, 7 Apr 23
44/50

Comments: 43 pages, 12 figures. Comments welcome!

A novel integrated Sachs-Wolfe effect from Early Dark Energy [CEA]

Posted on by

http://arxiv.org/abs/2304.02028


We study the nonlinear effects of minimally coupled, massless, cosmological scalar fields on the cosmic microwave background (CMB). These fields can exhibit post-recombination parametric resonance and subsequent nonlinear evolution leading to novel contributions to the gravitational potential. We compute the resulting contributions to the CMB temperature anisotropies through the time-variation of the gravitational potential (i.e., the integrated Sachs-Wolfe (ISW) effect). We find that fields that constitute 5% of the total energy density and become dynamical at $z_c \simeq 10^{4}$ can produce marginally observable ISW signals at multipoles $\ell \simeq 2000$. Fields that become dynamical at earlier times and/or have initial displacements at a flatter part of their potential, produce ISW contributions that are significantly larger and at higher multipoles. We calculate these dynamics and the resulting evolution of gravitational perturbations using analytic estimates alongside detailed nonlinear lattice simulations, which couple scalar fields and cosmological fluids to a perturbed metric. Finally, we discuss the possibility of detecting these features with future high-resolution CMB observations.

Read this paper on arXiv…

T. Smith, J. Jr., M. Amin, et. al.
Thu, 6 Apr 23
9/76

Comments: 12 pages, 6 figures, comments welcome

Measuring the photo-ionization rate, neutral fraction and mean free path of HI ionizing photons at $4.9 \leq z \leq 6.0$ from a large sample of XShooter and ESI spectra [CEA]

Posted on by

http://arxiv.org/abs/2304.02038


We measure the mean free path ($\lambda_{\rm mfp,HI}$), photo-ionization rate ($\langle \Gamma_{\rm HI} \rangle$) and neutral fraction ($\langle f_{\rm HI} \rangle$) of hydrogen in 12 redshift bins at $4.85<z<6.05$ from a large sample of moderate resolution XShooter and ESI QSO absorption spectra. The fluctuations in ionizing radiation field are modeled by post-processing simulations from the Sherwood suite using our new code ”EXtended reionization based on the Code for Ionization and Temperature Evolution” (EX-CITE). EX-CITE uses efficient Octree summation for computing intergalactic medium attenuation and can generate large number of high resolution $\Gamma_{\rm HI}$ fluctuation models. Our simulation with EX-CITE shows remarkable agreement with simulations performed with the radiative transfer code Aton and can recover the simulated parameters within $1\sigma$ uncertainty. We measure the three parameters by forward-modeling the Ly$\alpha$ forest and comparing the effective optical depth ($\tau_{\rm eff, HI}$) distribution in simulations and observations. The final uncertainties in our measured parameters account for the uncertainties due to thermal parameters, modeling parameters, observational systematics and cosmic variance. Our best fit parameters show significant evolution with redshift such that $\lambda_{\rm mfp,HI}$ and $\langle f_{\rm HI} \rangle$ decreases and increases by a factor $\sim 6$ and $\sim 10^{4}$, respectively from $z \sim 5$ to $z \sim 6$. By comparing our $\lambda_{\rm mfp,HI}$, $\langle \Gamma_{\rm HI} \rangle$ and $\langle f_{\rm HI} \rangle$ evolution with that in state-of-the-art Aton radiative transfer simulations and the Thesan and CoDa-III simulations, we find that our best fit parameter evolution is consistent with a model in which reionization completes by $z \sim 5.2$.

Read this paper on arXiv…

P. Gaikwad, M. Haehnelt, F. Davies, et. al.
Thu, 6 Apr 23
21/76

Comments: 30 pages (+14 pages appendices), 14 figures (+18 figures appendices); submitted to MNRAS; Main results are summarized in Fig. 10, Fig. 11 and Table 3

Constraining Horndeski theory with gravitational waves from coalescing binaries [CEA]

Posted on by

http://arxiv.org/abs/2304.02535


In the broad subclass of Horndeski theories with a luminal speed of gravitational waves, we derive gravitational waveforms emitted from a compact binary by considering the wave propagation on a spatially flat cosmological background. A scalar field nonminimally coupled to gravity gives rise to hairy neutron star (NS) solutions with a nonvanishing scalar charge, whereas black holes (BHs) do not have scalar hairs in such theories. A binary system containing at least one hairy neutron star modifies the gravitational waveforms in comparison to those of the BH-BH binary. Using the tensor gravitational waveforms, we forecast the constraints on a parameter characterizing the difference of scalar charges of NS-BH or NS-NS binaries for Advanced LIGO and Einstein Telescope. We illustrate how these constraints depend on redshift and signal-to-noise ratio, and on different possible priors. We show that in any case it is possible to constrain the scalar charge precisely, so that some scalarized NS solutions known in the literature can be excluded.

Read this paper on arXiv…

M. Quartin, S. Tsujikawa, L. Amendola, et. al.
Thu, 6 Apr 23
30/76

Comments: 21 pages, 5 figures, 2 tables. Comments are welcome

Quantitative constraints on modified gravity paradigms [CEA]

Posted on by

http://arxiv.org/abs/2304.02522


We use low-redshift background cosmology data to place quantitative constraints on three separate modified gravity models, each of which aims to explain the low-redshift acceleration through a different physical mechanism. The Lifshitz cosmology is effectively a parametric extension of the canonical $\Lambda$CDM model, where a time-dependent cosmological constant originates from vacuum energy. The Infinite Statistics model is also a parametric extension of $\Lambda$CDM, where the dark energy is dynamic and originates from the curvature of a dual space-time. We show that the data restricts the additional parameters in these models to be consistent with their $\Lambda$CDM values, and in particular that it implies that the theoretically predicted value for a dimensionless coupling parameter in the Lifshitz model is ruled out at more than six standard deviations. In the Regge-Teitelboim model, gravity is described by embedding the usual space-time manifold in a fixed higher-dimensional background, and there is no parametric $\Lambda$CDM limit. We study several separate realizations of the model, respectively introduced by Davidson, by Fabi \textit{et al.}, and by Stern \& Xu, and show that the first two are ruled out by the low-redshift data we use, while the latter is consistent with this data but requires a non-standard value of the matter density. Overall, our analysis highlights the tight constraints imposed by current data on the allowed low-redshift deviations from the standard $\Lambda$CDM background evolution.

Read this paper on arXiv…

S. Pinto, A. Cabral and C. Martins
Thu, 6 Apr 23
39/76

Comments: 11 pages, 8 figures, Phys. Rev. D (in press)

Robust and efficient CMB lensing power spectrum from polarization surveys [CEA]

Posted on by

http://arxiv.org/abs/2304.02584


Deep surveys of the CMB polarization have more information on the lensing signal than the quadratic estimators (QE) can capture. We showed in a recent work that a CMB lensing power spectrum built from a single optimized CMB lensing mass map, working in close analogy to state-of-the-art QE techniques, can result in an essentially optimal spectrum estimator at reasonable numerical cost. We extend this analysis here to account for real-life non-idealities including masking and realistic instrumental noise maps. As in the QE case, it is necessary to include small corrections to account for the estimator response to these anisotropies, which we demonstrate can be estimated easily from simulations. The realization-dependent debiasing of the spectrum remains robust, allowing unbiased recovery of the band powers even in cases where the statistical model used for the lensing map reconstruction is grossly wrong. This allows now robust and at the same time optimal CMB lensing constraints from CMB data, on all scales relevant for the inference of the neutrino mass, or other parameters of our cosmological model.

Read this paper on arXiv…

L. Legrand and J. Carron
Thu, 6 Apr 23
48/76

Comments: 12 pages, 8 figures, comments are welcome

Imprints of a Supercooled Universe in the Gravitational Wave Spectrum from a Cosmic String network [CEA]

Posted on by

http://arxiv.org/abs/2304.02636


A network of cosmic strings (CS), if present, would continue emitting gravitational waves (GW) as it evolves throughout the history of the Universe. This results in a characteristic broad spectrum making it a perfect source to infer the expansion history. In particular, a short inflationary period caused by a supercooled phase transition would cause a drop in the spectrum at frequencies corresponding to that event. However, the impact on the spectrum is similar to the ones caused by an early matter-dominated era or from particle production, making it difficult to disentangle these different physical origins. We point out that, in the case of a short inflationary period, the GW spectrum receives an additional contribution from the phase transition itself. This leads to a characteristic imprint of a peak on top of a wide plateau both visible at future GW observatories.

Read this paper on arXiv…

F. Ferrer, A. Ghoshal and M. Lewicki
Thu, 6 Apr 23
54/76

Comments: 12 pages without references, 2 Figures, comments are welcome

Using Elliptical Galaxy Kinematics to Compare of the Strength of Gravity in Cosmological Regions of Differing Gravitational Potential — A First Look [CEA]

Posted on by

http://arxiv.org/abs/2304.02123


Various models of modified gravity invoke “screening” mechanisms that are sensitive to the value of the local gravitational potential. This could have observable consequences for galaxies. These consequences might be seen by comparing two proxies for galaxy mass — their luminosity and their internal kinematics — as a function of local galaxy density. Motivated by this prospect, we have compared the observed properties of luminous red galaxies (LRGs) inside and outside of voids in the cosmic large scale structure. We used archival measurements of line widths, luminosities, redshifts, colors, and positions of galaxies in conjunction with recent void catalogs to construct comparison LRG samples inside and outside of voids. We fitted these two samples to the well-established fundamental plane of elliptical galaxies to constrain any differences between the inferred value of the Newtonian gravitational constant G for the two samples. We obtained a null result, with an upper limit on any fractional difference in G within and outside of cosmological voids to be $\alpha =\delta$$ G/G \sim$ 40\%. This upper bound is dominated by the small-number statistics of our N $\sim $ 100 within-void LRG sample. With the caveat that environmental effects could influence various parameters such as star formation, we estimate that a 1\% statistical limit on $\alpha$ could be attained with data from 10${^5}$ elliptical galaxies within voids. This is within the reach of future photometric and spectroscopic surveys, both of which are required to pursue this method.

Read this paper on arXiv…

E. Pedersen and C. Stubbs
Thu, 6 Apr 23
55/76

Comments: N/A

The CAMELS project: Expanding the galaxy formation model space with new ASTRID and 28-parameter TNG and SIMBA suites [CEA]

Posted on by

http://arxiv.org/abs/2304.02096


We present CAMELS-ASTRID, the third suite of hydrodynamical simulations in the Cosmology and Astrophysics with MachinE Learning (CAMELS) project, along with new simulation sets that extend the model parameter space based on the previous frameworks of CAMELS-TNG and CAMELS-SIMBA, to provide broader training sets and testing grounds for machine-learning algorithms designed for cosmological studies. CAMELS-ASTRID employs the galaxy formation model following the ASTRID simulation and contains 2,124 hydrodynamic simulation runs that vary 3 cosmological parameters ($\Omega_m$, $\sigma_8$, $\Omega_b$) and 4 parameters controlling stellar and AGN feedback. Compared to the existing TNG and SIMBA simulation suites in CAMELS, the fiducial model of ASTRID features the mildest AGN feedback and predicts the least baryonic effect on the matter power spectrum. The training set of ASTRID covers a broader variation in the galaxy populations and the baryonic impact on the matter power spectrum compared to its TNG and SIMBA counterparts, which can make machine-learning models trained on the ASTRID suite exhibit better extrapolation performance when tested on other hydrodynamic simulation sets. We also introduce extension simulation sets in CAMELS that widely explore 28 parameters in the TNG and SIMBA models, demonstrating the enormity of the overall galaxy formation model parameter space and the complex non-linear interplay between cosmology and astrophysical processes. With the new simulation suites, we show that building robust machine-learning models favors training and testing on the largest possible diversity of galaxy formation models. We also demonstrate that it is possible to train accurate neural networks to infer cosmological parameters using the high-dimensional TNG-SB28 simulation set.

Read this paper on arXiv…

Y. Ni, S. Genel, D. Anglés-Alcázar, et. al.
Thu, 6 Apr 23
56/76

Comments: N/A

A Test of Gravity with Pulsar Timing Arrays [CEA]

Posted on by

http://arxiv.org/abs/2304.02640


A successful measurement of the Stochastic Gravitational Wave Background (SGWB) in Pulsar Timing Arrays (PTAs) would open up a new window through which to test the predictions of General Relativity (GR). We consider how these measurements might reveal deviations from GR by studying the overlap reduction function — the quantity that in GR is approximated by the Hellings-Downs curve — in some sample modifications of gravity, focusing on the generic prediction of a modified dispersion relation for gravitational waves. We find a distinct signature of such modifications to GR — a shift in the minimum angle of the angular distribution — and demonstrate that this shift is quantitatively sensitive to any change in the phase velocity. In a given modification of gravity, this result can be used, in some regions of parameter space, to distinguish the effect of a modified dispersion relation from that due to the presence of extra polarization modes.

Read this paper on arXiv…

Q. Liang, M. Lin and M. Trodden
Thu, 6 Apr 23
58/76

Comments: 22 pages, 4 figures

Glass-Like Random Catalogues for Two-Point Estimates on the Light Cone [CEA]

Posted on by

http://arxiv.org/abs/2304.02040


We introduce grlic, a publicly available Python tool for generating glass-like point distributions with a radial density profile $n(r)$ as it is observed in large-scale surveys of galaxy distributions on the past light cone. Utilising these glass-like catalogues, we assess the bias and variance of the Landy-Szalay (LS) estimator of the first three two-point correlation function (2PCF) multipoles in halo and particle catalogues created with the cosmological N-body code gevolution. Our results demonstrate that the LS estimator calculated with the glass catalogues is biased by less than $10^{-4}$ with respect to the estimate derived from Poisson-sampled random catalogues, for all multipoles considered and on all but the smallest scales. Additionally, the estimates derived from glass-like catalogues exhibit significantly smaller standard deviation than estimates based on commonly used Poisson-sampled random catalogues of comparable size. The standard deviation $\sigma$ of the estimate depends on a power of the number of objects $N_R$ in the random catalogue; we find a power law $\sigma \propto \alpha^{-0.9}$ for glass-like random catalogues as opposed to $\sigma \propto N_R^{-0.48}$ using Poisson-sampled random catalogues. Given a required precision, this allows for a much reduced number of objects in the glass-like random catalogues used for the LS estimate of the 2PCF multipoles, significantly reducing the computational costs of each estimate.

Read this paper on arXiv…

S. Schulz
Thu, 6 Apr 23
66/76

Comments: N/A

Sibling Rivalry: SNeIa Diversity and the Hubble Tension [CEA]

Posted on by

http://arxiv.org/abs/2304.01831


Thermonuclear supernovae, or Type-Ia supernovae (SNeIa), are an essential tool of cosmology. Precise cosmological constraints are extracted from a Hubble diagram defined by homogeneous distance indicators, but supernova homogeneity is not guaranteed. The degree of heterogeneity within the SNeIa parent population is unknown. In addition, event selections and standardization procedures are based on empirical, optically-measured observables rather than fundamental thermonuclear properties. Systematics are a natural consequence of event selection from a diverse parent population. Quantifying the impact of diversity-driven systematics is crucial to optimizing SNeIa as cosmic probes. In this work, the empirical observables are used to calibrate previously unidentified diversity-driven systematic uncertainties. The foundation of this approach is the concept of “supernova siblings”, two or more supernovae hosted by the same parent galaxy. Sibling-based calibrations isolate intrinsic differences between supernovae; they control for source distance and host galaxy dependencies that can conceal systematics or lead to their underestimation. Newly calibrated distance modulus uncertainties are approximately an order of magnitude larger than previously reported. The physical origin of these uncertainties is plausibly attributed to the diverse thermonuclear scenarios responsible for SNeIa and the inhomogeneous apparent magnitudes induced by this diversity. Systematics mitigation strategies are discussed. Cosmological parameter constraints extracted from a re-analysis of the Pantheon+ SNeIa dataset are weaker than previously reported. Agreement with early-Universe parameter estimates is achieved for a $\Lambda$CDM cosmology, including a reduction of the Hubble Tension from $\sim$5$\sigma$ to <1$\sigma$.

Read this paper on arXiv…

R. Miller
Wed, 5 Apr 23
1/62

Comments: 10 pages, 6 figures, 1 table. Submitted to ApJL

Growth of Perturbations in Energy-Momentum-Squared Gravity [CEA]

Posted on by

http://arxiv.org/abs/2304.01571


Employing the spherical collapse (SC) formalism, we investigate the linear evolution of the matter overdensity for energy-momentum-squared gravity (EMSG) which in practical phenomenological terms, one may imagine as an extension of \LambdaCDM model of cosmology. The underlying model while still having a cosmological constant, is a nonlinear matter extension of the general theory of relativity and includes modification terms dominating in the high energy regimes i.e., early universe. Considering the Friedman-Robertson-Walker (FRW) background in the presence of a cosmological constant, we find the effects of the modifications arising from EMSG on the growth of perturbations at the early stages of the universe. By taking into account both possible negative, and positive values of the model parameter of EMSG, we discuss its role in the evolution of the matter density contrast and growth function in the level of linear perturbations. While EMSG leaves imprints distinguishable from \LambdaCDM, we find that the negative range of the ESMG model parameter is not well-behaved indicating an anomaly in the parameter space of the model. In this regard, for the evaluation of the galaxy cluster number count in the framework of EMSG, we equivalently provide an analysis of the number count of the gravitationally collapsed objects (or the dark matter halos). We show that the galaxy cluster number count decreases compared to the \LambdaCDM model. In agreement with the hierarchical model of structure formation, in EMSG cosmology also the more massive structures are less abundant, meaning that form at later times.

Read this paper on arXiv…

B. Farsi, A. Sheykhi and M. Khodadi
Wed, 5 Apr 23
4/62

Comments: 9 pages, 8 figures

Fast multiscale galaxy cluster detection with weak lensing: towards a mass-selected sample [CEA]

Posted on by

http://arxiv.org/abs/2304.01812


The sensitivity and wide area reached by ongoing and future wide-field optical surveys allows for the detection of an increasing number of galaxy clusters uniquely through their weak lensing (WL) signal. This motivates the development of new methods to analyse the unprecedented volume of data faster and more efficiently. Here we introduce a new multi-scale WL detection method based on application of wavelet filters to the convergence maps. We compare our results to those obtained from four commonly-used single scale approaches based on the application of aperture mass filters to the shear in real and Fourier space. The method is validated on Euclid-like mocks from the DUSTGRAIN-pathfinder simulations. We introduce a new matching procedure that takes into account the theoretical signal-to-noise of detection by WL and the filter size. We perform a complete analysis of the filters, and a comparison of the purity and the completeness of the resulting detected catalogues. We show that equivalent results are obtained when the detection is undertaken in real and Fourier space, and when the algorithms are applied to the shear and the convergence. We show that the multiscale method applied to the convergence is faster and more efficient at detecting clusters than single scale methods applied to the shear. We obtained an increase of 25% in the number of detections while maintaining the same purity compared to the most up-to-date aperture mass filter. We analyse the detected catalogues and quantify the efficiency of the matching procedure, showing in particular that less than 5% of the detections from the multiscale method can be ascribed to line-of-sight alignments. The method is well-adapted to the more sensitive, wider-area, optical surveys that will be available in the near future, and paves the way to cluster samples that are as near as possible to being selected by total matter content.

Read this paper on arXiv…

G. Leroy, S. Pires, G. Pratt, et. al.
Wed, 5 Apr 23
5/62

Comments: 24 pages, 13 figures, submitted to A&A

Kinetic relaxation and Bose-star formation in multicomponent dark matter- I [CEA]

Posted on by

http://arxiv.org/abs/2304.01985


Using wave kinetics, we estimate the emergence time-scale of gravitating Bose-Einstein condensates/Bose stars in the kinetic regime for a general multicomponent Schr\”{o}dinger-Poisson (SP) system. We identify some effects of the diffusion and friction pieces in the wave-kinetic Boltzmann equation (at leading order in perturbation theory) and provide estimates for the kinetic nucleation rate of condensates. We test our analysis using full $3+1$ dimensional simulations of multicomponent SP system. With an eye towards applications to multicomponent dark matter, we investigate two general cases in detail. First is a massive spin-$s$ field with $N=2s+1$ components (scalar $s=0$, vector $s=1$ and tensor $s=2$). We find that for a democratic population of different components, the condensation time-scale is $\tau_{(s)}\approx \tau_0\times N$, where $\tau_0$ is the condensation time scale for the scalar case. Second is the case of two scalars with different boson masses. In this case, we map-out how the condensation time depends on the ratios of their average mass densities and boson masses, revealing competition and assistance between components, and a guide towards which component condenses first. For instance, with $m_1 < m_2$ and not too disparate mass densities, we verify that the time scale of condensation of the first species quickly becomes independent of $m_2/m_1$, whereas for equal average number densities, the emergence time scale decreases with increasing $m_2/m_1$.

Read this paper on arXiv…

M. Jain, M. Amin, J. Thomas, et. al.
Wed, 5 Apr 23
13/62

Comments: 8 pages + 3 appendices, 5 figures. Videos from simulations are available at this https URL

Primordial black holes from single-field inflation: a fine-tuning audit [CEA]

Posted on by

http://arxiv.org/abs/2304.01997


All single-field inflationary models invoke varying degrees of tuning in order to account for cosmological observations. Mechanisms that generate primordial black holes (PBHs) from enhancement of primordial power at small scales posit inflationary potentials that transiently break scale invariance and possibly adiabaticity over a range of modes. This requires additional tuning on top of that required to account for observations at scales probed by cosmic microwave background (CMB) anisotropies. In this paper we study the parametric dependence of various single-field models of inflation that enhance power at small scales and quantify the degree to which coefficients in the model construction have to be tuned in order for certain observables to lie within specified ranges. We find significant tuning: changing the parameters of the potentials by between one part in a hundred and one part in $10^8$ (depending on the model) is enough to change the power spectrum peak amplitude by an order one factor. The fine-tuning of the PBH abundance is larger still by 1-2 orders of magnitude. We highlight the challenges imposed by this tuning on any given model construction. Furthermore, polynomial potentials appear to require significant additional fine-tuning to also match the CMB observations.

Read this paper on arXiv…

P. Cole, A. Gow, C. Byrnes, et. al.
Wed, 5 Apr 23
20/62

Comments: 23 pages, 5 figures

Constraints on the Epoch of Reionization with Roman Space Telescope and the Void Probability Function of Lyman-Alpha Emitters [CEA]

Posted on by

http://arxiv.org/abs/2304.01837


We use large simulations of Lyman-Alpha Emitters with different fractions of ionized intergalactic medium to quantify the clustering of Ly$\alpha$ emitters as measured by the Void Probability function (VPF), and how it evolves under different ionization scenarios. We quantify how well we might be able to distinguish between these scenarios with a deep spectroscopic survey using the future Nancy Grace Roman Space Telescope. Since Roman will be able to carry out blind spectroscopic surveys of Ly$\alpha$ emitters continuously between $7<z<12$ to sensitivities of at least $10^{-17}$ erg sec$^{-1}$ over a wide field of view, it can measure the epoch of reionization as well as the pace of ionization of the intergalactic medium (IGM). We compare deep Roman surveys covering roughly 1, 4, and 16 deg$^2$, and quantify what constraints on reionization the VPF may find for these surveys. A survey of 1 deg$^2$ would distinguish between very late reionization and early reionization to 3$\sigma$ near $z=7.7$ with the VPF. The VPF of a 4 deg$^2$ survey can distinguish between slow vs.\ fast, and early vs.\ late, reionization at $> 3-4\sigma$ at several redshifts between $7<z<9$. However, a survey of 13-16 deg$^2$ would allow the VPF to give several robust constraints ($>5-8\sigma$) across the epoch of reionization, and would yield a detailed history of the reionization of the IGM and its effect on Lyman-$\alpha$ Emitter clustering.

Read this paper on arXiv…

L. Perez, S. Malhotra, J. Rhoads, et. al.
Wed, 5 Apr 23
29/62

Comments: 19 total pages, 7 total figures, appendix with 3 additional figures

On the primordial black hole formation in hybrid inflation [CEA]

Posted on by

http://arxiv.org/abs/2304.01249


We revisit the scenario of primordial black hole (PBH) formation from large curvature perturbations generated during the waterfall phase transition in hybrid inflation models. In a minimal setup considered in the literature, the mass and abundance of PBHs are correlated and astrophysical size PBHs tend to be overproduced. This is because a longer length scale for curvature perturbations (or a larger PBH mass) requires a longer waterfall regime with a flatter potential, which results in overproduction of curvature perturbations. However, in this paper, we discuss that the higher-dimensional terms for the inflaton potential affect the dynamics during the waterfall phase transition and show that astrophysical size PHBs of order $10^{17\text{–}23} \, {\rm g}$ (which can explain the whole dark matter) can form in some parameter space consistently with any existing constraints. The scenario can be tested by observing the induced gravitational waves from scalar perturbations by future gravitational wave experiments, such as LISA.

Read this paper on arXiv…

Y. Tada and M. Yamada
Wed, 5 Apr 23
40/62

Comments: 13 pages, 8 figures

A Field-Level Multi-Probe Analysis of the CMB, ISW, and the Galaxy Density Maps [CEA]

Posted on by

http://arxiv.org/abs/2304.01387


Extracting information from cosmic surveys is often done in a two-step process, construction of maps and then summary statistics such as two-point functions. We use simulations to demonstrate the advantages of a general Bayesian framework that consistently combines different cosmological experiments on the field level, and reconstructs both the maps and cosmological parameters. We apply our method to jointly reconstruct the primordial CMB, the Integrated Sachs Wolfe effect, and 6 tomographic galaxy density maps on the full sky on large scales along with several cosmological parameters. While the traditional maximum a posterior estimator has both 2-point level and field-level bias, the new approach yields unbiased cosmological constraints and improves the signal-to-noise ratio of the maps.

Read this paper on arXiv…

A. Zhou and S. Dodelson
Wed, 5 Apr 23
50/62

Comments: N/A

The Dark Energy Survey Supernova Program: Corrections on photometry due to wavelength-dependent atmospheric effects [CEA]

Posted on by

http://arxiv.org/abs/2304.01858


Wavelength-dependent atmospheric effects impact photometric supernova flux measurements for ground-based observations. We present corrections on supernova flux measurements from the Dark Energy Survey Supernova Program’s 5YR sample (DES-SN5YR) for differential chromatic refraction (DCR) and wavelength-dependent seeing, and we show their impact on the cosmological parameters $w$ and $\Omega_m$. We use $g-i$ colors of Type Ia supernovae (SNe Ia) to quantify astrometric offsets caused by DCR and simulate point spread functions (PSFs) using the GalSIM package to predict the shapes of the PSFs with DCR and wavelength-dependent seeing. We calculate the magnitude corrections and apply them to the magnitudes computed by the DES-SN5YR photometric pipeline. We find that for the DES-SN5YR analysis, not accounting for the astrometric offsets and changes in the PSF shape cause an average bias of $+0.2$ mmag and $-0.3$ mmag respectively, with standard deviations of $0.7$ mmag and $2.7$ mmag across all DES observing bands (\textit{griz}) throughout all redshifts. When the DCR and seeing effects are not accounted for, we find that $w$ and $\Omega_m$ are lower by less than $0.004\pm0.02$ and $0.001\pm0.01$ respectively, with $0.02$ and $0.01$ being the $1\sigma$ statistical uncertainties. Although we find that these biases do not limit the constraints of the DES-SN5YR sample, future surveys with much higher statistics, lower systematics, and especially those that observe in the $u$ band will require these corrections as wavelength-dependent atmospheric effects are larger at shorter wavelengths. We also discuss limitations of our method and how they can be better accounted for in future surveys.

Read this paper on arXiv…

J. Lee, M. Acevedo, M. Sako, et. al.
Wed, 5 Apr 23
54/62

Comments: 15 pages, 13 figures, accepted by the Astronomical Journal

Hyper Suprime-Cam Year 3 Results: Cosmology from Galaxy Clustering and Weak Lensing with HSC and SDSS using the Minimal Bias Model [CEA]

Posted on by

http://arxiv.org/abs/2304.00705


We present cosmological parameter constraints from a blind joint analysis of three two-point correlation functions measured from the Year 3 Hyper Suprime-Cam (HSC-Y3) imaging data, covering 416 deg$^2$, and the SDSS DR11 spectroscopic galaxies spanning the redshift range $[0.15, 0.70]$. We subdivide the SDSS galaxies into three volume-limited samples separated in redshift, each of which acts as a large-scale structure tracer characterized by the measurement of the projected correlation function, $w_{\rm p}(R)$. We also use the measurements of the galaxy-galaxy weak lensing signal $\Delta \Sigma(R)$ for each of these SDSS samples which act as lenses for a secure sample of source galaxies selected from the HSC-Y3 shape catalog based on their photometric redshifts. We combine these measurements with the cosmic shear correlation functions, $\xi_{\pm}(\vartheta)$, measured for our HSC source sample. We model these observables with the minimal bias model of the galaxy clustering observables in the context of a flat $\Lambda$CDM cosmology. We use conservative scale cuts, $R>12$ and $8~h^{-1}$Mpc, for $\Delta\Sigma$ and $w_{\rm p}$, respectively, where the minimal bias model is valid, in addition to conservative prior on the residual bias in the mean redshift of the HSC photometric source galaxies. Our baseline analysis yields $S_8=0.775^{+0.043}_{-0.038}$ (68% C.I.) for the $\Lambda$CDM model, after marginalizing over uncertainties in other parameters. Our value of $S_8$ is consistent with that from the Planck 2018 data, but the credible interval of our result is still relatively large. Our results are statistically consistent with those of a companion paper, which extends this analysis to smaller scales with an emulator-based halo model.

Read this paper on arXiv…

S. Sugiyama, H. Miyatake, S. More, et. al.
Tue, 4 Apr 23
2/111

Comments: 29 pages, 17 figures, 4 tables, for coordinated submission to PRD with other HSC Y3 weak lensing cosmology papers – see this https URL

Hyper Suprime-Cam Year 3 Results: Cosmology from Galaxy Clustering and Weak Lensing with HSC and SDSS using the Emulator Based Halo Model [CEA]

Posted on by

http://arxiv.org/abs/2304.00704


We present cosmology results from a blinded joint analysis of cosmic shear, $\xi_{\pm}(\vartheta)$, galaxy-galaxy weak lensing, $\Delta!\Sigma(R)$, and projected galaxy clustering, $w_{\rm p}(R)$, measured from the Hyper Suprime-Cam three-year (HSC-Y3) shape catalog and the Sloan Digital Sky Survey (SDSS) DR11 spectroscopic galaxy catalog – a 3$\times$2pt cosmology analysis. We define luminosity-cut samples of SDSS galaxies to serve as the tracers of $w_{\rm p}$ and as the lens samples for $\Delta!\Sigma$ in three spectroscopic redshift bins spanning the range $0.15<z<0.7$. For the $\xi_{\pm}$ and $\Delta!\Sigma$ measurements, we use a single source sample over 416 deg$^2$, selected from HSC-Y3 based on having photometric redshifts (photo-$z$) greater than 0.75. For cosmological parameter inference, we use Dark Emulator combined with a halo occupation distribution prescription to model $w_{\rm p}$ and $\Delta!\Sigma$ down to quasi-nonlinear scales. In our baseline analysis we employ an uninformative flat prior of the residual photo-$z$ error to model a residual bias in the mean redshift of HSC source galaxies. We obtain a robust constraint on the cosmological parameters for the flat $\Lambda$CDM model: $S_8=\sigma_8(\Omega_{\rm m}/0.3)^{0.5}=0.763^{+0.040}{-0.036}$ (68% C.I.), or the best-constrained parameter given by $S’_8=\sigma_8(\Omega{\rm m}/0.3)^{0.22}=0.721\pm 0.028$, determined with about 4% fractional precision. Our HSC-Y3 data exhibits about 2.5$\sigma$ tension with the Planck inferred $S_8$ value for the $\Lambda$CDM model, and hints at a non-zero residual photo-$z$ bias implying that the true mean redshift of the HSC galaxies at $z\gtrsim 0.75$ is higher than that implied by the original photo-$z$ estimates.

Read this paper on arXiv…

H. Miyatake, S. Sugiyama, M. Takada, et. al.
Tue, 4 Apr 23
8/111

Comments: 39 pages, 25 figures, 5 tables, for coordinated submission to PRD with other HSC Y3 weak lensing cosmology papers – see this https URL arXiv admin note: text overlap with arXiv:2111.02419

Systematic error mitigation for the PIXIE Fourier transform spectrometer [CEA]

Posted on by

http://arxiv.org/abs/2304.00091


The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission concept to measure the spectrum and polarization of the cosmic microwave background. Cosmological signals are small compared to the instantaneous instrument noise, requiring strict control of instrumental signals. The instrument design provides multiple levels of null operation, signal modulation, and signal differences, with only few-percent systematic error suppression required at each level. Jackknife tests based on discrete instrument symmetries provide an independent means to identify, model, and remove remaining instrumental signals. We use detailed time-ordered simulations, including realistic performance and tolerance parameters, to evaluate the instrument response to broad classes of systematic errors for both spectral distortions and polarization. The largest systematic errors contribute additional white noise at the few-percent level compared to the dominant photon noise. Coherent instrumental effects which do not integrate down are smaller still, and remain several orders of magnitude below the targeted cosmological signals.

Read this paper on arXiv…

A. Kogut, D. Fixsen, N. Aghanim, et. al.
Tue, 4 Apr 23
26/111

Comments: 37 pages including 23 figures

The most fundamental question of all times [CEA]

Posted on by

http://arxiv.org/abs/2304.01011


In the last few decades, reading the literature, we realized that we Astronomers have a strong preference to undertake very ambitious projects, and search for answers to the most fundamental questions in the history of the entire Universe. After running multiple times into such cardinal quest, the curiosity became no more sustainable and we had to find out. To our greater surprise, in the last few decades we had been restlessly participating to this superhuman endevour. Therefore we hereby explore the roots and grounds of this fundamental search, through the past decades, centuries and millennia.

Read this paper on arXiv…

S. Berta, A. Poisson, K. Scherz, et. al.
Tue, 4 Apr 23
29/111

Comments: April fools!

Stochastic Multiple Fields Inflation: Diffusion Dominated Regime [CEA]

Posted on by

http://arxiv.org/abs/2304.00577


We study multiple fields inflation in diffusion dominated regime using stochastic $\delta N$ formalism. The fields are under pure Brownian motion in a dS background with boundaries in higher dimensional field space. This setup can be realized towards the final stages of the ultra slow-roll setup where the classical drifts fall off exponentially and the perturbations are driven by quantum kicks. We consider both symmetric and asymmetric boundaries with absorbing and reflective boundary conditions and calculate the average number of e-folds, the first crossing probabilities and the power spectrum. We study the primordial black holes (PBHs) formation in this setup and calculate the mass fraction and the contribution of PBHs in dark matter energy density for various higher dimensional field spaces.

Read this paper on arXiv…

K. Asadi, A. Nassiri-Rad and H. Firouzjahi
Tue, 4 Apr 23
34/111

Comments: 40 pages, 15 figures

Primordial Stochastic Gravitational Wave Backgrounds from a Sharp Feature in Three-field Inflation [CEA]

Posted on by

http://arxiv.org/abs/2304.00065


The detection of a primordial stochastic gravitational wave background has the potential to reveal unprecedented insights into the early universe, and possibly into the dynamics of inflation. Generically, UV-complete inflationary models predict an abundance of light scalars, so any inflationary stochastic background may well be formed in a model with several interacting degrees of freedom. The stochastic backgrounds possible from two-field inflation have been well-studied in the literature, but it is unclear how similar they are to the possibilities from many-field inflation. In this work, we study stochastic backgrounds from more-than-two field inflation for the first time, focusing on the scalar-induced background produced by a brief turn in three-field space. We find an analytic expression for the enhancement in the power spectrum as a function of the turn rate and the torsion, and show that unique signatures of three-field dynamics are possible in the primordial power spectrum and gravitational wave spectrum. We confirm our analytic results with a suite of numerical simulations and find good agreement in the shape and amplitude of the power spectra. We also comment on the detection prospects in LISA and other future detectors. We do not expect the moderately large growth of the inflationary perturbations necessary for detection to cause a breakdown of perturbation theory, but this must be verified on a case-by-case basis for specific microphysical models to make a definitive claim.

Read this paper on arXiv…

V. Aragam, S. Paban and R. Rosati
Tue, 4 Apr 23
35/111

Comments: 28 pages, 7 figures

Cosmological evolution of Witten superconducting string networks [CEA]

Posted on by

http://arxiv.org/abs/2304.00053


We consider the evolution of current-carrying cosmic string networks described by the charge-velocity-dependent one scale (CVOS) model beyond the linear equation of state regime, specifically focusing on the Witten superconducting model. We find that, generically, for almost chiral currents, the network evolution reduces dynamically to that of the linear case, which has been discussed in our previous work. However, the Witten model introduces a maximum critical current which constrains the network scaling behaviour during the radiation era when currents can grow and approach this limit. Unlike the linear model, only if the energy density in the critical current is comparable to the bare string tension will there be substantial backreaction on the network evolution, thus changing the observational predictions of superconducting strings from those expected from a Nambu-Goto network. During the matter era, if there are no external sources, then dynamical effects dilute these network currents and they disappear at late times.

Read this paper on arXiv…

I. Rybak, C. Martins, P. Peter, et. al.
Tue, 4 Apr 23
36/111

Comments: 10 pages, 5 figures

Cosmology from the integrated shear 3-point correlation function: simulated likelihood analyses with machine-learning emulators [CEA]

Posted on by

http://arxiv.org/abs/2304.01187


The integrated shear 3-point correlation function $\zeta_{\pm}$ measures the correlation between the local shear 2-point function $\xi_{\pm}$ and the 1-point shear aperture mass in patches of the sky. Unlike other higher-order statistics, $\zeta_{\pm}$ can be efficiently measured from cosmic shear data, and it admits accurate theory predictions on a wide range of scales as a function of cosmological and baryonic feedback parameters. Here, we develop and test a likelihood analysis pipeline for cosmological constraints using $\zeta_{\pm}$. We incorporate treatment of systematic effects from photometric redshift uncertainties, shear calibration bias and galaxy intrinsic alignments. We also develop an accurate neural-network emulator for fast theory predictions in MCMC parameter inference analyses. We test our pipeline using realistic cosmic shear maps based on $N$-body simulations with a DES Y3-like footprint, mask and source tomographic bins, finding unbiased parameter constraints. Relative to $\xi_{\pm}$-only, adding $\zeta_{\pm}$ can lead to $\approx 10-25\%$ improvements on the constraints of parameters like $A_s$ (or $\sigma_8$) and $w_0$. We find no evidence in $\xi_{\pm} + \zeta_{\pm}$ constraints of a significant mitigation of the impact of systematics. We also investigate the impact of the size of the apertures where $\zeta_{\pm}$ is measured, and of the strategy to estimate the covariance matrix ($N$-body vs. lognormal). Our analysis solidifies the strong potential of the $\zeta_{\pm}$ statistic and puts forward a pipeline that can be readily used to improve cosmological constraints using real cosmic shear data.

Read this paper on arXiv…

Z. Gong, A. Halder, A. Barreira, et. al.
Tue, 4 Apr 23
40/111

Comments: 21 pages, 11 figures, 3 tables. Comments welcome

Supermassive Dark Star candidates seen by JWST? [CEA]

Posted on by

http://arxiv.org/abs/2304.01173


The first generation of stars in the Universe is yet to be observed. There are two leading theories for those objects that mark the beginning of the cosmic dawn: hydrogen burning Population~III stars and Dark Stars, made of hydrogen and helium but powered by Dark Matter heating. The latter can grow to become supermassive ($M_\star\sim 10^6\Msun$) and extremely bright ($L\sim 10^9L_\odot$). We show that each of the following three objects: JADES-GS-z13-0, JADES-GS-z12-0, and JADES-GS-z11-0 (at redshifts $z\in[11,14]$) are consistent with a Supermassive Dark Star interpretation, thus identifying, for the first time, Dark Star candidates.

Read this paper on arXiv…

C. Ilie, J. Paulin and K. Freese
Tue, 4 Apr 23
57/111

Comments: N/A

A 1.3% distance to M33 from HST Cepheid photometry [CEA]

Posted on by

http://arxiv.org/abs/2304.00037


We present a low-dispersion period-luminosity relation (PL) based on 154 Cepheids in Messier 33 (M33) with Hubble Space Telescope (HST) photometry from the PHATTER survey. Using high-quality ground-based light curves, we recover Cepheid phases and amplitudes for multi-epoch HST data and we perform template fitting to derive intensity-averaged mean magnitudes. HST observations in the SH0ES near-infrared Wesenheit system significantly reduce the effect of crowding relative to ground-based data, as seen in the final PL scatter of $\sigma$ = 0.11 mag. We adopt the absolute calibration of the PL based on HST observations in the Large Magellanic Cloud (LMC) and a distance derived using late-type detached eclipsing binaries to obtain a distance modulus for M33 of $\mu$ = 24.622 $\pm$ 0.030 mag (d = 840 $\pm$ 11 kpc), a best-to-date precision of 1.3%. We find very good agreement with past Cepheid-based measurements. Several TRGB estimates bracket our result while disagreeing with each other. Finally, we show that the flux contribution from star clusters hosting Cepheids in M33 does not impact the distance measurement and we find only 3.7% of the sample is located in (or nearby) young clusters. M33 offers one of the best sites for the cross-calibration of many primary distance indicators. Thus, a precise independent geometric determination of its distance would provide a valuable new anchor to measure the Hubble constant.

Read this paper on arXiv…

L. Breuval, A. Riess, L. Macri, et. al.
Tue, 4 Apr 23
59/111

Comments: Submitted to ApJ, comments welcome

Hyper Suprime-Cam Year 3 Results: Cosmology from Cosmic Shear Power Spectra [CEA]

Posted on by

http://arxiv.org/abs/2304.00701


We measure weak lensing cosmic shear power spectra from the three-year galaxy shear catalog of the Hyper Suprime-Cam (HSC) Subaru Strategic Program imaging survey. The shear catalog covers $416 \ \mathrm{deg}^2$ of the northern sky, with a mean $i$-band seeing of 0.59 arcsec and an effective galaxy number density of 15 $\mathrm{arcmin}^{-2}$ within our adopted redshift range. With an $i$-band magnitude limit of 24.5 mag, and four tomographic redshift bins spanning $0.3 \leq z_{\mathrm{ph}} \leq 1.5$ based on photometric redshifts, we obtain a high-significance measurement of the cosmic shear power spectra, with a signal-to-noise ratio of approximately 26.4 in the multipole range $300<\ell<1800$. The accuracy of our power spectrum measurement is tested against realistic mock shear catalogs, and we use these catalogs to get a reliable measurement of the covariance of the power spectrum measurements. We use a robust blinding procedure to avoid confirmation bias, and model various uncertainties and sources of bias in our analysis, including point spread function systematics, redshift distribution uncertainties, the intrinsic alignment of galaxies and the modeling of the matter power spectrum. For a flat $\Lambda$CDM model, we find $S_8 \equiv \sigma_8 (\Omega_m/0.3)^{0.5} =0.776^{+0.032}_{-0.033}$, which is in excellent agreement with the constraints from the other HSC Year 3 cosmology analyses, as well as those from a number of other cosmic shear experiments. This result implies a $\sim$$2\sigma$-level tension with the Planck 2018 cosmology. We study the effect that various systematic errors and modeling choices could have on this value, and find that they can shift the best-fit value of $S_8$ by no more than $\sim$$0.5\sigma$, indicating that our result is robust to such systematics.

Read this paper on arXiv…

R. Dalal, X. Li, A. Nicola, et. al.
Tue, 4 Apr 23
64/111

Comments: 35 pages, 18 figures, 6 tables, for coordinated submission to PRD with other HSC Y3 weak lensing cosmology papers – see this https URL

Hyper Suprime-Cam Year 3 Results: Measurements of Clustering of SDSS-BOSS Galaxies, Galaxy-Galaxy Lensing and Cosmic Shear [CEA]

Posted on by

http://arxiv.org/abs/2304.00703


We use the Sloan Digital Sky Survey (SDSS) BOSS galaxies and their overlap with approximately 416 sq. degree of deep $grizy$-band imaging from the Subaru Hyper Suprime-Cam Survey (HSC). We measure three two-point correlations that form the basis of the cosmological inference presented in our companion papers, Miyatake et al. and Sugiyama et al. We use three approximately volume limited subsamples of spectroscopic galaxies by their $i$-band magnitude from the SDSS-BOSS: LOWZ (0.1<z<0.35), CMASS1 (0.43<z<0.55) and CMASS2 (0.55<z<0.7), respectively. We present high signal-to-noise ratio measurements of the projected correlation functions of these galaxies, which is expected to be proportional to the matter correlation function times the bias of galaxies on large scales. In order to break the degeneracy between the amplitude of the matter correlation and the bias of these galaxies, we use the distortions of the shapes of galaxies in HSC due to weak gravitational lensing, to measure the galaxy-galaxy lensing signal, which probes the galaxy-matter cross-correlation of the SDSS-BOSS galaxies. We also measure the cosmic shear correlation functions from HSC galaxies which is related to the projected matter correlation function. We demonstrate the robustness of our measurements with a variety of systematic tests. Our use of a single sample of HSC source galaxies is crucial to calibrate any residual systematic biases in the inferred redshifts of our galaxies. We also describe the construction of a suite of mocks: i) spectroscopic galaxy catalogs which obey the clustering and abundance of each of the three SDSS-BOSS subsamples, and ii) galaxy shape catalogs which obey the footprint of the HSC survey and have been appropriately sheared by the large-scale structure expected in a $\Lambda$-CDM model. We use these mock catalogs to compute the covariance of each of our observables.

Read this paper on arXiv…

S. More, S. Sugiyama, H. Miyatake, et. al.
Tue, 4 Apr 23
68/111

Comments: 30 pages, 24 figures, for coordinated submission to PRD with other HSC Y3 weak lensing cosmology papers – see this https URL

Quasi-Molecular mechanism of cosmological recombination: a scheme of calculation [CEA]

Posted on by

http://arxiv.org/abs/2304.00072


For a quasi-molecular mechanism of cosmological recombination, a scheme of calculation based on a rigorous quantum-mechanical approach is elaborated. The probability of free-bound radiative transition into an excited state of a quasi-molecule temporarily formed by a colliding electron and two nearest neighboring protons is derived in a closed algebraic form.

Read this paper on arXiv…

T. Kereselidze, I. Noselidze and Z. Machavariani
Tue, 4 Apr 23
90/111

Comments: 10 pages, 2 figures

Hyper Suprime-Cam Year 3 Results: Cosmology from Cosmic Shear Two-point Correlation Functions [CEA]

Posted on by

http://arxiv.org/abs/2304.00702


We perform a blinded cosmology analysis with cosmic shear two-point correlation functions (2PCFs) measured from more than 25 million galaxies in the Hyper Suprime-Cam three-year shear catalog in four tomographic redshift bins ranging from 0.3 to 1.5. After conservative masking and galaxy selection, the survey covers 416 deg$^2$ of the northern sky with an effective galaxy number density of 15 arcmin$^{-2}$ over the four redshift bins. The 2PCFs adopted for cosmology analysis are measured in the angular range: $7.1 < \theta/{\rm arcmin} < 56.6$ for $\xi_+$ and $31.2 <\theta/{\rm arcmin} < 248$ for $\xi_-$, with a total signal-to-noise ratio of 26.6. We apply a conservative, wide, flat prior on the photometric redshift errors on the last two tomographic bins, and the relative magnitudes of the cosmic shear amplitude across four redshift bins allow us to calibrate the photometric redshift errors. With this flat prior on redshift errors, we find $\Omega_{\rm m}=0.256_{-0.044}^{+0.056}$ and $S_8\equiv \sigma_8 \sqrt{\Omega_{\rm m}/0.3}=0.769_{-0.034}^{+0.031}$ (both 68\% CI) for a flat $\Lambda$ cold dark matter cosmology. We find, after unblinding, that our constraint on $S_8$ is consistent with the Fourier space cosmic shear and the 3$\times$2pt analyses on the same HSC dataset. We carefully study the potential systematics from astrophysical and systematic model uncertainties in our fiducial analysis using synthetic data, and report no biases (including projection bias in the posterior space) greater than $0.5\sigma$ in the estimation of $S_8$. Our analysis hints that the mean redshifts of the two highest tomographic bins are higher than initially estimated. In addition, a number of consistency tests are conducted to assess the robustness of our analysis. Comparing our result with Planck-2018 cosmic microwave background observations, we find a ~$2\sigma$ tension for the $\Lambda$CDM model.

Read this paper on arXiv…

X. Li, T. Zhang, S. Sugiyama, et. al.
Tue, 4 Apr 23
98/111

Comments: 36 pages, 29 figures, 4 tables, for coordinated submission to PRD with other HSC Y3 weak lensing cosmology papers – see this https URL

Detecting cosmic voids via maps of geometric-optics parameters [CEA]

Posted on by

http://arxiv.org/abs/2304.00591


Curved-spacetime geometric-optics maps derived from a deep photometric survey should contain information about the three-dimensional matter distribution and thus about cosmic voids in the survey, despite projection effects. We explore to what degree sky-plane geometric-optics maps can reveal the presence of intrinsic three-dimensional voids. We carry out a cosmological $N$-body simulation and place it further than a gigaparsec from the observer, at redshift 0.5. We infer three-dimensional void structures using the watershed algorithm. Independently, we calculate a surface overdensity map and maps of weak gravitational lensing and geometric-optics scalars. We propose and implement a heuristic algorithm for detecting (projected) radial void profiles from these maps. We find in our simulation that given the sky-plane centres of the three-dimensional watershed-detected voids, there is significant evidence of correlated void centres in the surface overdensity $\Sigma$, the averaged weak-lensing tangential shear $\overline{\gamma_\perp}$, the Sachs expansion $\theta$, and the Sachs shear modulus $\lvert\sigma\rvert$. Recovering the centres of the three-dimensional voids from the sky-plane information alone is significant given the weak-lensing shear $\overline{\gamma_\perp}$, the Sachs expansion $\theta$, or the Sachs shear $\lvert\sigma\rvert$, but not significant for the surface overdensity $\Sigma$. Void radii are uncorrelated between three-dimensional and two-dimensional voids; our algorithm is not designed to distinguish voids that are nearly concentric in projection. This investigation shows preliminary evidence encouraging observational studies of gravitational lensing through individual voids, either blind or with spectroscopic/photometric redshifts. The former case – blind searches – should generate falsifiable predictions of intrinsic three-dimensional void centres.

Read this paper on arXiv…

M. Peper, B. Roukema and K. Bolejko
Tue, 4 Apr 23
101/111

Comments: 14 pages, 8 figures, 3 tables, zenodo.7792910 at this https URL, archived git at this https URL, live git at this https URL

Spectroscopy of QUBRICS quasar candidates: 1672 new redshifts and a Golden Sample for the Sandage Test of the Redshift Drift [CEA]

Posted on by

http://arxiv.org/abs/2304.00362


The QUBRICS (QUasars as BRIght beacons for Cosmology in the Southern hemisphere) survey aims at constructing a sample of the brightest quasars with z>~2.5, observable with facilities in the Southern Hemisphere. QUBRICS makes use of the available optical and IR wide-field surveys in the South and of Machine Learning techniques to produce thousands of bright quasar candidates of which only a few hundred have been confirmed with follow-up spectroscopy. Taking advantage of the recent Gaia Data Release 3, which contains 220 million low-resolution spectra, and of a newly developed spectral energy distribution fitting technique, designed to combine the photometric information with the Gaia spectroscopy, it has been possible to measure 1672 new secure redshifts of QUBRICS candidates, with a typical uncertainty $\sigma_z = 0.02$. This significant progress of QUBRICS brings it closer to (one of) its primary goals: providing a sample of bright quasars at redshift 2.5 < z < 5 to perform the Sandage test of the cosmological redshift drift. A Golden Sample of seven quasars is presented that makes it possible to carry out this experiment in about 1500 hours of observation in 25 years, using the ANDES spectrograph at the 39m ELT, a significant improvement with respect to previous estimates.

Read this paper on arXiv…

S. Cristiani, M. Porru, F. Guarneri, et. al.
Tue, 4 Apr 23
111/111

Comments: 11 pages, 10 figures, accepted for publication in MNRAS

Scale-Invariant Model for Gravitational Waves and Dark Matter [CEA]

Posted on by

http://arxiv.org/abs/2303.18122


We have conducted a revised analysis of the first-order phase transition that is associated with symmetry breaking in a classically scale-invariant model that has been extended with a new $SU(2)$ gauge group. By incorporating recent developments in the understanding of supercooled phase transitions, we were able to calculate all of its features and significantly limit the parameter space. We were also able to predict the gravitational wave spectra generated during this phase transition and found that this model is well-testable with LISA. Additionally, we have made predictions regarding the relic dark matter abundance. Our predictions are consistent with observations but only within a narrow part of the parameter space. We have placed significant constraints on the supercool dark matter scenario by improving the description of percolation and reheating after the phase transition, as well as including the running of couplings. Finally, we have also analyzed the renormalization-scale dependence of our results.

Read this paper on arXiv…

A. Karam, M. Kierkla and B. Świeżewska
Mon, 3 Apr 23
13/53

Comments: 18+9 pages, 9 figures, invited talk given at CORFU2022, summarizing the results of arXiv:2210.07075

An IllustrisTNG View of the Caustic Technique for Galaxy Cluster Mass Estimation [CEA]

Posted on by

http://arxiv.org/abs/2303.18147


The TNG300-1 run of the IllustrisTNG simulations includes 1697 clusters of galaxies with $M_{200c}>10^{14}$M$\odot$ covering the redshift range $0.01-1.04$. We build mock spectroscopic redshift catalogues of simulated galaxies within these clusters and apply the caustic technique to estimate the cumulative cluster mass profiles. We compute the total true cumulative mass profile from the 3D simulation data and calculate the ratio of caustic mass to total 3D mass, $\mathcal{F}\beta$, as a function of cluster-centric distance and identify the radial range where $\mathcal{F}\beta$ is roughly constant. The filling factor, $\mathcal{F}\beta=0.41\pm 0.08$, is constant on a plateau that covers a wide cluster-centric distance range, $(0.6-4.2)R_{200c}$. This calibration is insensitive to redshift. The calibrated caustic mass profiles are unbiased, with an average uncertainty of $23\%$. At $R_{200c}$, the average $M^C/M^{3D}=1.03\pm 0.22$; at $2R_{200c}$, the average $M^C/M^{3D}=1.02\pm 0.23$. Simulated galaxies are unbiased tracers of the mass distribution. IllustrisTNG is a broad statistical platform for application of the caustic technique to large samples of clusters with spectroscopic redshifts for $\gtrsim 200$ members in each system. These observations will allow extensive comparisons with weak lensing masses and will complement other techniques for measuring the growth rate of structure in the universe.

Read this paper on arXiv…

M. Pizzardo, M. Geller, S. Kenyon, et. al.
Mon, 3 Apr 23
15/53

Comments: 11 pages, 9 figures, 2 tables

Boosting Line Intensity Map Signal-to-Noise with the Ly-$α$ Forest Cross-Correlation [CEA]

Posted on by

http://arxiv.org/abs/2303.17632


We forecast the prospects for cross-correlating future line intensity mapping (LIM) surveys with the current and future Ly-$\alpha$ forest data. We use large cosmological hydrodynamic simulations to model the expected emission signal for the CO rotational transition in the COMAP LIM experiment at the 5-year benchmark and the Ly-$\alpha$ forest absorption signal for various surveys, including eBOSS, DESI, and PFS. We show that CO$\times$Ly-$\alpha$ forest can significantly enhance the detection signal-to-noise ratio of CO, with a $200$ to $300 \%$ improvement when cross-correlated with the forest observed in the Prime Focus Spectrograph (PFS) survey and a $50$ to $75\%$ enhancement for the currently available eBOSS or the upcoming DESI observations. We compare to the signal-to-noise improvements expected for a galaxy survey and show that CO$\times$Ly-$\alpha$ is competitive with even a spectroscopic galaxy survey in raw signal-to-noise. Furthermore, our study suggests that the clustering of CO emission is tightly constrained by CO$\times$Ly-$\alpha$ forest, due to the increased signal-to-noise ratio and the simplicity of Ly-$\alpha$ absorption power spectrum modeling. Any foreground contamination or systematics are expected not to be shared between LIM surveys and Ly-$\alpha$ forest observations; this provides an unbiased inference. Our findings highlight the potential benefits of utilizing the Ly-$\alpha$ forest to aid in the initial detection of signals in line intensity experiments. For example, we also estimate that [CII]$\times$Ly-$\alpha$ forest measurements from EXCLAIM and DESI/eBOSS, respectively, should have a larger signal-to-noise ratio than planned [CII]$\times$quasar observations by about an order of magnitude. Our results can be readily applied to actual data thanks to the observed quasar spectra in eBOSS Stripe 82, which overlaps with several LIM surveys.

Read this paper on arXiv…

M. Qezlou, S. Bird, A. Lidz, et. al.
Mon, 3 Apr 23
17/53

Comments: Codes and the produced data are available at this https URL

Cosmological Signatures of Mass Varying Dark Matter [CEA]

Posted on by

http://arxiv.org/abs/2303.17947


Nontrivial dark sector physics continues to be an interesting avenue in our quest to the nature of dark matter. In this paper, we study the cosmological signatures of mass-varying dark matter where its mass changes from zero to a nonzero value in the early Universe. We compute the changes in various observables, such as, the matter and the cosmic microwave background anisotropy power spectrum. We explain the origin of the effects and point out a qualitative similarity between this model and a warm dark matter cosmology with no sudden mass transition. We also do a simple frequentist analysis of the linear matter power spectrum to estimate the constraint on the parameters of this model from latest cosmological observation data.

Read this paper on arXiv…

A. Das, S. Das and S. Sethi
Mon, 3 Apr 23
23/53

Comments: 7 pages, 6 figures

Hydrodynamical constraints on bubble wall velocity [CEA]

Posted on by

http://arxiv.org/abs/2303.18216


Terminal velocity reached by bubble walls in first order phase transitions is an important parameter determining both primordial gravitational-wave spectrum and production of baryon asymmetry in models of electroweak baryogenesis. We developed a numerical code to study the real-time evolution of expanding bubbles and investigate how their walls reach stationary states. Our results agree with profiles obtained within the so-called bag model with very good accuracy, however, not all such solutions are stable and realised in dynamical systems. Depending on the exact shape of the potential there is always a range of wall velocities where no steady state solutions exist. This behaviour in deflagrations was explained by hydrodynamical obstruction where solutions that would heat the plasma outside the wall above the critical temperature and cause local symmetry restoration are forbidden. For even more affected hybrid solutions causes are less straight forward, however, we provide a simple numerical fit allowing one to verify if a solution with a given velocity is allowed simply by computing the ratio of the nucleation temperature to the critical one for the potential in question.

Read this paper on arXiv…

T. Krajewski, M. Lewicki and M. Zych
Mon, 3 Apr 23
39/53

Comments: N/A

LyAl-Net: A high-efficiency Lyman-$α$ forest simulation with a neural network [CEA]

Posted on by

http://arxiv.org/abs/2303.17939


The inference of cosmological quantities requires accurate and large hydrodynamical cosmological simulations. Unfortunately, their computational time can take millions of CPU hours for a modest coverage in cosmological scales ($\approx (100 {h^{-1}}\,\text{Mpc})^3)$). The possibility to generate large quantities of mock Lyman-$\alpha$ observations opens up the possibility of much better control on covariance matrices estimate for cosmological parameters inference, and on the impact of systematics due to baryonic effects. We present a machine learning approach to emulate the hydrodynamical simulation of intergalactic medium physics for the Lyman-$\alpha$ forest called LyAl-Net. The main goal of this work is to provide highly efficient and cheap simulations retaining interpretation abilities about the gas field level, and as a tool for other cosmological exploration. We use a neural network based on the U-net architecture, a variant of convolutional neural networks, to predict the neutral hydrogen physical properties, density, and temperature. We train the LyAl-Net model with the Horizon-noAGN simulation, though using only 9% of the volume. We also explore the resilience of the model through tests of a transfer learning framework using cosmological simulations containing different baryonic feedback. We test our results by analysing one and two-point statistics of emulated fields in different scenarios, as well as their stochastic properties. The ensemble average of the emulated Lyman-$\alpha$ forest absorption as a function of redshift lies within 2.5% of one derived from the full hydrodynamical simulation. The computation of individual fields from the dark matter density agrees well with regular physical regimes of cosmological fields. The results tested on IllustrisTNG100 showed a drastic improvement in the Lyman-$\alpha$ forest flux without arbitrary rescaling.

Read this paper on arXiv…

C. Boonkongkird, G. Lavaux, S. Peirani, et. al.
Mon, 3 Apr 23
48/53

Comments: N/A

The role of soft photon injection and heating in 21 cm cosmology [CEA]

Posted on by

http://arxiv.org/abs/2303.17311


The ARCADE radio excess and EDGES measurement remain puzzling. A link between the two has been previously considered, however, in this work we highlight an important related effect that was not analyzed in detail before. By performing cosmological thermalization calculations with soft photon injection using {\tt CosmoTherm}, we show that for the 21 cm signal generation the interplay between enhanced radio spectral distortions and the associated heating can hide a significant radio excess before the reionzation era. We illustrate this effect for a simple power-law soft photon source in decaying particle scenarios. Even if simplistic, the uncovered link between CMB spectral distortions and 21 cm cosmology should apply to a much broader range of scenarios. This could significantly affect the constraints derived from existing and future 21 cm observations on the evolution of the ambient radio background. In particular, scenarios that would be ruled out by existing data without heating could become viable solutions once the heating is accounted for in the modelling. Our calculations furthermore highlight the importance of global 21 cm observations reaching into the dark ages, where various scenarios can potentially be distinguished.

Read this paper on arXiv…

S. Acharya, B. Cyr and J. Chluba
Fri, 31 Mar 23
6/70

Comments: Comments welcome

Fully inhomogeneous non-linear dynamics of axion inflation [CEA]

Posted on by

http://arxiv.org/abs/2303.17436


We study the non-linear dynamics of axion inflation, capturing for the first time the inhomogeneity and full dynamical range, till the end of inflation. Accounting for inhomogeneous effects during backreaction leads to a number of new relevant results, compared to spatially homogeneous studies: {\it i)} the number of extra efoldings beyond slow roll inflation increases very rapidly with the coupling, {\it ii)} oscillations of the inflaton velocity are attenuated, {\it iii)} the tachyonic gauge field helicity spectrum is smoothed out (i.e.~the spectral oscillatory features disappear), broadened, and shifted to smaller scales, and {\it iv)} the non-tachyonic helicity is excited, reducing the chiral asymmetry, now scale dependent. Our results are expected to impact strongly on the phenomenology and observability of axion inflation, including gravitational wave generation and primordial black hole production.

Read this paper on arXiv…

D. Figueroa, J. Lizarraga, A. Urio, et. al.
Fri, 31 Mar 23
25/70

Comments: 9 pages including Supplemental Material; 4 figures

Non-thermal moduli production during preheating in $α$-attractor inflation models [CEA]

Posted on by

http://arxiv.org/abs/2303.17383


Production of gravitationally coupled light moduli fields must be suppressed in the early universe, so that its decay products do not alter Big Bang Nucleosynthesis (BBN) predictions for light elements. On the other hand, the moduli quanta can be copiously produced non-thermally during preheating after the end of inflation. In this work, we study the production of moduli in the $\alpha$-attractor inflationary model through parametric resonances. For our case, where the inflationary potential at its minimum is quartic, the inflaton field self-resonates, and subsequently induces large production of moduli particles. We find that this production is suppressed for small values of $\alpha$. Combining semi-analytical estimation and numerical lattice simulations, we infer the parametric dependence on $\alpha$ and learn that $\alpha$ needs to be $\lesssim 10^{-8}\,m_{\rm Pl}^2$ to be consistent with BBN. This in turn predicts an upper bound on the energy scale of inflation and on the reheating temperature. Further, it implies an extremely small tensor-to-scalar ratio that quantifies the amplitude of primordial gravitational waves over large scales.

Read this paper on arXiv…

K. Alam, M. Bastero-Gil, K. Dutta, et. al.
Fri, 31 Mar 23
33/70

Comments: 24 pages, 8 figures

On the impact of $f(Q)$ gravity on the Large Scale Structure [CEA]

Posted on by

http://arxiv.org/abs/2303.17341


We investigate the exponential $f(Q)$ symmetric teleparallel gravitation, namely $f(Q)=Q+\alpha Q_0(1-e^{-\beta\sqrt{Q/Q_0}})$ using \texttt{ME-GADGET} code to probe the structure formation with box sizes $L_{\mathrm{box}}=10/100$ Mpc$/h$ and middle resolution $N_p^{1/3}=512$. To reproduce viable cosmology within the aforementioned modified gravity theory, we first perform Markov Chain Monte Carlo (MCMC) sampling on OHD/BAO/Pantheon datasets and constrain a parameter space. Furthermore, we also derive theoretical values for deceleration parameter $q(z)$, statefinder pair ${r,s}$ and effective gravitational constant $G_{\mathrm{eff}}$, perform $Om(z)$ diagnostics. While carrying out N-body+SPH simulations, we derive CDM+baryons over density/temperature/mean molecular weight fields, matter power spectrum (both 2/3D, with/without redshift space distortions), bispectrum, two-point correlation function and halo mass function. Results for small and big simulation box sizes are therefore properly compared, halo mass function is related to the Seth-Tormen theoretical prediction and matter power spectrum to the standard \texttt{CAMB} output.

Read this paper on arXiv…

O. Sokoliuk, S. Arora, S. Praharaj, et. al.
Fri, 31 Mar 23
43/70

Comments: MNRAS accepted version

Exploring the possible evolution of the mass density power-law index of strong gravitational lenses with a model-independent method [CEA]

Posted on by

http://arxiv.org/abs/2303.17407


In this work, we adopt a cosmological model-independent approach for the first time to test the question of whether the mass density power-law index($\gamma$) of the strong gravitational lensing system(SGLS) evolves with redshift, and the JLA SNe Ia sample and the quasar sample from Risaliti \& Lusso (2019) are used to provide the luminosity distances to be calibrated. Our work is based on the flat universe assumption and the cosmic distance duality relation. A reliable data-matching method is used to pair SGLS-SNe and SGLS-quasar. By using the maximum likelihood method to constrain the luminosity distance and $\gamma$ index, we obtain the likelihood function values for the evolved and non-evolved cases, and then use the Akaike weights and the BIC selection weights to compare the advantages and disadvantages of these two cases. We find that the $\gamma$ index is slightly more likely to be a non-evolutionary model for $\gamma=2$ in the case of the currently used samples with low redshift ($z_l<\sim$0.66). With Akaike weights, the relative probability is 66.3\% versus 33.7\% and 69.9\% versus 30.1\% for the SGLS+SNe Ia sample and SGLS+quasar sample, respectively, and with BIC selection weights, the relative probability is 87.4\% versus 12.6\% and 52.0\% versus 48.0\% for the two samples. In the evolving case for the relatively low redshift lens (SGLS+SNe Ia), with redshift 0.0625 to 0.659, $\gamma= 2.058^{+0.041}{-0.040}-0.136^{+0.163}{-0.165}z$. At high redshift (SGLS+quasar ), with redshift 0.0625 to 1.004, $\gamma= 2.051^{+0.076}{-0.077}-0.171^{+0.214}{-0.196}z$. Although not the more likely model, this evolved $\gamma$ case also fits the data well, with a negative and mild evolution for both low and high redshift samples.

Read this paper on arXiv…

J. Hu
Fri, 31 Mar 23
45/70

Comments: 9 pages, 7 figures

Primordial black holes and stochastic inflation beyond slow roll: I — noise matrix elements [CEA]

Posted on by

http://arxiv.org/abs/2303.17375


Primordial Black Holes (PBHs) may form in the early Universe, from the gravitational collapse of large density perturbations, generated by large quantum fluctuations during inflation. Since PBHs form from rare over-densities, their abundance is sensitive to the tail of the primordial probability distribution function (PDF) of the perturbations. It is therefore important to calculate the full PDF of the perturbations, which can be done non-perturbatively using the ‘stochastic inflation’ framework. In single field inflation models generating large enough perturbations to produce an interesting abundance of PBHs requires violation of slow roll. It is therefore necessary to extend the stochastic inflation formalism beyond slow roll. A crucial ingredient for this are the stochastic noise matrix elements of the inflaton potential. We carry out analytical and numerical calculations of these matrix elements for a potential with a feature which violates slow roll and produces large, potentially PBH generating, perturbations. We find that the transition to an ultra slow-roll phase results in the momentum induced noise terms becoming larger than the field noise whilst each of them falls exponentially for a few e-folds. The noise terms then start rising with their original order restored, before approaching constant values which depend on the nature of the slow roll parameters in the post transition epoch. This will significantly impact the quantum diffusion of the coarse-grained inflaton field, and hence the PDF of the perturbations and the PBH mass fraction.

Read this paper on arXiv…

S. Mishra, E. Copeland and A. Green
Fri, 31 Mar 23
53/70

Comments: 47 pages, 8 figures

Small scale clustering of BOSS galaxies: dependence on luminosity, color, age, stellar mass, specific star formation rate and other properties [CEA]

Posted on by

http://arxiv.org/abs/2303.17095


We measure and analyze galaxy clustering and the dependence on luminosity, color, age, stellar mass and specific star formation rate using Baryon Oscillation Spectroscopic Survey (BOSS) galaxies at $0.48<z<0.62$. We fit the monopole and quadrupole moments of the two-point correlation function (2PCF) and its projection on scales of $0.1$ — $60.2h^{-1}$Mpc, after having split the catalog in a variety of ways. We find that the clustering dependence is consistent with previous well-established results showing the broad trends expected: For example, that brighter, redder, older, more massive and quenched galaxies are more strongly clustered. We also investigate the dependence on additional parameters previously derived from stellar population synthesis model fits to the spectra. We find that galaxy clustering depends on look-back formation time at a low level, while it has little dependence on metallicity. To understand the physics behind these trends, we fit the clustering with a simulation-based emulator to simultaneously model cosmology and galaxy bias using a Halo Occupation Distribution framework. After marginalizing parameters determining the background cosmology, galaxy bias, and a scaling parameter to decouple halo velocity field, we find that the growth rate of large scale structure as determined by the redshift-space distortions is consistent with previous analysis using the full sample and is independent of the galaxy selection. This demonstrates that cosmological inference using small scale clustering measurements is robust to changes in the catalog selection.

Read this paper on arXiv…

Z. Zhai, W. Percival and H. Guo
Fri, 31 Mar 23
63/70

Comments: 16 pages, 13+2 figures, comments welcome

Gravitational wave microlensing by dressed primordial black holes [CEA]

Posted on by

http://arxiv.org/abs/2303.17601


We study gravitational wave microlensing by primordial black holes (PBHs), accounting for the effect of a particle dark matter minihalo surrounding them. Such minihaloes are expected when PBHs make up only a fraction of all dark matter. We find that the LIGO-Virgo detections imply a $1\sigma$ bound on the abundance of PBHs heavier than $50 M_{\odot}$. The next generation observatories can potentially probe PBHs as light as $0.01 M_\odot$ and down to $2\times10^{-4}$ fraction of all dark matter. We also show that these detectors can distinguish between dressed and naked PBHs, providing a novel way to study the distribution of particle dark matter around black holes and potentially shed light on the origins of black holes.

Read this paper on arXiv…

J. Urrutia, V. Vaskonen and H. Veermäe
Fri, 31 Mar 23
69/70

Comments: N/A

Implications of GWTC-3 on primordial black holes from vacuum bubbles [CEA]

Posted on by

http://arxiv.org/abs/2303.16810


The population of black holes inferred from the detection of gravitational waves by the LIGO-Virgo-KAGRA collaboration has revealed interesting features in the properties of black holes in the universe. We analyze the GWTC-3 dataset assuming the detected black holes have both astrophysical and primordial origins. In particular, we consider primordial black holes forming from vacuum bubbles that nucleate during inflation, with their mass distribution described by a broken power law. We find that more than half of the events could come from primordial black hole mergers. Astrophysical black holes are mainly responsible for the peak in mass distribution at $\sim 10M_\odot$ indicated by GWTC-3; whereas primordial black holes are responsible for the massive black holes, as well as the peak at $\sim 30M_\odot$. We also discuss the implications on the primordial black hole formation mechanism and the underlying inflationary model.

Read this paper on arXiv…

J. He, H. Deng, Y. Piao, et. al.
Thu, 30 Mar 23
1/66

Comments: N/A

SPARC HSBs, and LSBs, the surface density of dark matter haloes, and MOND [CEA]

Posted on by

http://arxiv.org/abs/2303.16658


In this paper, we use SPARC’s HSBs, and LSBs galaxies to verify two issues. The first one is related to one claim of \citep{Donato} D09, namely: is the DM surface density (DMsd) a constant universal quantity, equal to $\log{(\rm \Sigma/M_\odot pc^{-2})}=2.15 \pm 0.2$, or does it depend on the baryon surface density of the system? The second one, is based on a MOND prediction that for HSBs the DMsd is constant, and equal to $\log{(\rm \Sigma/M_\odot pc^{-2})}=2.14$, while for LSBs the surface density is not constant and takes values that are smaller than for HSBs and D09 prediction \citep{Milgrom2009}. We find that HSBs shows a constant DMsd vs magnitude as in D09, and a constant DMsd vs $\Sigma_{\rm eff}$ as in MOND prediction, for HSBs with $\Sigma_{\rm eff}>200 L_\odot/pc^2$, and $\Sigma_{\rm eff}>300 L_\odot/pc^2$. However, the value of the DMsd is larger, $\Sigma \simeq 2.61$ (in the case of the DMsd-magnitude with $\Sigma_{\rm eff}>300 L_\odot/pc^2$), and $\Sigma \simeq 2.54$ (in the case of the surface DMsd-surface brightness with $\Sigma_{\rm eff}>200 L_\odot/pc^2$). This value slightly depends on the threshold to determine wheter a galaxy is HSB. In the case of LSBs, for $\Sigma_{\rm eff}<100 L_\odot/pc^2$, and $\Sigma_{\rm eff}<25 L_\odot/pc^2$, the surface density vs magnitude, for lower magnitudes, is approximately equal to that predicted by D09, but several galaxies, for magnitude $M>-17$, have smaller values than those predicted by D09. The DMsd vs $\Sigma_{\rm eff}$ shows a similar behavior in qualitative, but not quantitative, agreement with MOND predictions. In summary, in the case of HSBs both D09 and MOND are in qualitative, but not quantitative, agreement with the data. In the case of LSBs D09 is mainly in disagreement with the data, and MOND only in qualitative agreement with them.

Read this paper on arXiv…

A. Popolo
Thu, 30 Mar 23
12/66

Comments: 31 pages, 4 figures

New Insight on Neutrino Dark Matter Interactions from Small-Scale CMB Observations [CEA]

Posted on by

http://arxiv.org/abs/2303.16895


We revisit the possibility of using cosmological observations to constrain models that involve interactions between neutrinos and dark matter. We show that small-scale measurements of the cosmic microwave background with a few per cent accuracy are critical to uncover unique signatures from models with tiny couplings that would require a much higher sensitivity at lower multipoles, such as those probed by the Planck satellite. We analyze the high-multipole data released by the Atacama Cosmology Telescope, both independently and in combination with Planck and Baryon Acoustic Oscillation measurements, finding a compelling preference for a non-vanishing coupling, $\log_{10}u_{\nu \textrm{DM}}=-5.20^{+1.2}_{-0.74}$ at 68% CL. This aligns with other CMB-independent probes, such as Lyman-$\alpha$. We illustrate how this coupling could be accounted for in the presence of dark matter interactions with a sterile neutrino.

Read this paper on arXiv…

P. Brax, C. Bruck, E. Valentino, et. al.
Thu, 30 Mar 23
15/66

Comments: 6 pages, 3 figures

Constraining inflationary potentials with inflaton PBHs [CEA]

Posted on by

http://arxiv.org/abs/2303.16428


If, after primordial inflation, the universe undergoes a relatively long reheating period, it could present a phase of matter domination supported by the oscillating inflaton field. During this epoch, small perturbations from the inflaton that reenter the cosmological horizon could virialize to form \textit{inflaton} structures. If the primordial overdensities are large enough, their associated inflaton structures could collapse to form primordial black holes (PBHs) [L.E.Padilla, J.C.Hidalgo and K.A.Malik, Phys.Rev.D, vol.106, p.023519, Jul 2022; hereinafter P1]. For this to happen at a considerable rate, the primordial power spectrum should be enhanced at small scales, a feature typically induced in single-field inflation through an ultra-slow roll phase (produced by a nearly-inflection point in the inflationary potential). In this article we consider two specific inflationary potentials that present this nearly-inflection point and we look at the PBH formation rate through the mechanism proposed in P1. We report on constraints to these two specific models from the bounds to PBH abundances. This serves as an illustration of the usefulness of the PBH formation mechanism proposed in P1.

Read this paper on arXiv…

L. Padilla, J. Hidalgo and G. German
Thu, 30 Mar 23
16/66

Comments: 7 figures, 4 tables. Comments are welcome

Forming intracluster gas in a galaxy protocluster at a redshift of 2.16 [CEA]

Posted on by

http://arxiv.org/abs/2303.16226


Galaxy clusters are the most massive gravitationally bound structures in the Universe, comprising thousands of galaxies and pervaded by a diffuse, hot “intracluster medium” (ICM) that dominates the baryonic content of these systems. The formation and evolution of the ICM across cosmic time is thought to be driven by the continuous accretion of matter from the large-scale filamentary surroundings and dramatic merger events with other clusters or groups. Until now, however, direct observations of the intracluster gas have been limited only to mature clusters in the latter three-quarters of the history of the Universe, and we have been lacking a direct view of the hot, thermalized cluster atmosphere at the epoch when the first massive clusters formed. Here we report the detection (about $6\sigma$) of the thermal Sunyaev-Zeldovich (SZ) effect in the direction of a protocluster. In fact, the SZ signal reveals the ICM thermal energy in a way that is insensitive to cosmological dimming, making it ideal for tracing the thermal history of cosmic structures. This result indicates the presence of a nascent ICM within the Spiderweb protocluster at redshift $z=2.156$, around 10 billion years ago. The amplitude and morphology of the detected signal show that the SZ effect from the protocluster is lower than expected from dynamical considerations and comparable with that of lower-redshift group-scale systems, consistent with expectations for a dynamically active progenitor of a local galaxy cluster.

Read this paper on arXiv…

L. Mascolo, A. Saro, T. Mroczkowski, et. al.
Thu, 30 Mar 23
53/66

Comments: 18 pages (main text + methods), 10 figures, 2 tables; published online in Nature on March 29th, 2023

Effective Field Theory of Intrinsic Alignments at One Loop Order: a Comparison to Dark Matter Simulations [CEA]

Posted on by

http://arxiv.org/abs/2303.15565


We test the regime of validity of the effective field theory (EFT) of intrinsic alignments (IA) at the one-loop level by comparing with 3D halo shape statistics in N-body simulations. This model is based on the effective field theory of large-scale structure (EFT of LSS) and thus a theoretically well-motivated extension of the familiar non-linear alignment (NLA) model and the tidal-alignment-tidal-torquing (TATT) model. It contains a total of $8$ free bias parameters. Specifically, we measure the dark matter halo shape-shape multipoles $P_{EE}^{(0)}(k), P_{EE}^{(2)}(k), P_{BB}^{(0)}(k), P_{BB}^{(2)}(k)$ as well as the matter-shape multipoles $P_{\delta E}^{(0)}(k), P_{\delta E}^{(2)}(k)$ from the simulations and perform a joint fit to determine the largest wavenumber $k_{\text{max}}$ up to which the theory predictions from the EFT of IA are consistent with the measurements. We find that the EFT of IA is able to describe intrinsic alignments of dark matter halos up to $k_\text{max}=0.30\,h/\text{Mpc}$ at $z=0$. This demonstrates a clear improvement over other existing alignment models like NLA and TATT, which are only accurate up to $k_\text{max}=0.05\,h/\text{Mpc}$ . We examine the posterior distributions of the higher-order bias parameters, and show that their inclusion is necessary to describe intrinsic alignments in the quasi-linear regime. Further, the EFT of IA is able to accurately describe the auto-spectrum of intrinsic alignment B-modes, in contrast to the other alignment models considered.

Read this paper on arXiv…

T. Bakx, T. Kurita, N. Chisari, et. al.
Wed, 29 Mar 23
28/73

Comments: 35 pages, 2 tables, 6 figures

GEO-FPT: a model of the galaxy bispectrum at mildly non-linear scales [CEA]

Posted on by

http://arxiv.org/abs/2303.15510


We present GEO-FPT (Geometric Fitted Perturbation Theory), a new model for the galaxy bispectrum anisotropic signal in redshift space, with functional form rooted in perturbation theory. It also models the dependence of the bispectrum with the geometric properties of the triangles in Fourier space, and has a broader regime of validity than state-of-the-art theoretical models based on perturbation theory. We calibrate the free parameters of this model using high-resolution dark matter simulations and perform stringent tests to show that GEO-FPT describes the galaxy bispectrum accurately up to scales of $k\simeq0.12 h{\rm Mpc}^{-1}$ for different cosmological models, as well as for biased tracers of the dark matter field, considering a survey volume of $100$ (Gpc $h^{-1})^3$. In particular, a joint analysis of the power spectrum and bispectrum anisotropic signals, taking into account their full covariance matrix, reveals that the relevant physical quantities — the BAO peak position (along and across the line-of-sight), and the growth of structure parameters times the amplitude of dark matter fluctuations, $f\sigma_8$– are recovered in an unbiased way, with an accuracy better than $0.4\%$ and $2\%$ respectively (which is our $2\sigma$ statistical limit of the systematic error estimate). In addition, the bispectrum signal breaks the $f\sigma_8$ degeneracy without detectable bias: $f$ and $\sigma_8$ are recovered with better than $2.7\%$ and $3.8\%$ accuracy respectively (which is our $2\sigma$ statistical limit of the systematic error estimate).
GEO-FPT boosts the applicability of the bispectrum signal of galaxy surveys beyond the current limitation of $k\lesssim 0.08\,h$ Mpc$^{-1}$ % and makes the bispectrum a key statistic to unlock the information content from the mildly non-linear regime in the on-going and forthcoming galaxy redshift surveys.

Read this paper on arXiv…

S. Novell-Masot, H. Gil-Marín and L. Verde
Wed, 29 Mar 23
38/73

Comments: 37 pages, 14 figures. To be submitted to JCAP, comments welcome

Anticipating the XRISM search for the decay of resonantly produced sterile neutrino dark matter [CEA]

Posted on by

http://arxiv.org/abs/2303.15513


The resonantly produced sterile neutrino ($N_1$) of the neutrino minimal standard model ($\nu$MSM) is a compelling dark matter candidate, especially in the reported possible detection of $N_1$ with mass $m_\mathrm{s}=7.1$~keV in X-ray decay. This particle will be accessible to the XRISM X-ray mission over the next 12 months. We revisit the physics behind $N_1$ and the uncertainty in its parameters. We compare predictions for the $m_\mathrm{s}=7.1$keV $N_1$ mixing angle, $\sin^{2}(2\theta)$, and half-mode mass, $M_\mathrm{hm}$, to existing X-ray observations and structure formation constraints. The strongest available constraints rule out $N_1$ as a dark matter candidate, and a more optimistic reading of the data prefers $\sin^{2}(2\theta)=5\times10^{-11}$ and $M_\mathrm{hm}=3.5\times10^{8}$$\mathrm{M}_{\odot}$. We highlight that the most promising upcoming opportunity for a detection is to find a line of velocity dispersion $\sim500$$\mathrm{kms^{-1}}$ in the Virgo cluster with XRISM, and then draw up a list of future objects of study to determine: (i) whether the line is from dark matter generally, and (ii) if from dark matter, whether that candidate is indeed $N_1$.

Read this paper on arXiv…

M. Lovell
Wed, 29 Mar 23
43/73

Comments: 13 pages, 7 figures. To be submitted to MNRAS. Contact: lovell@hi.is

Squeezed bispectrum and one-loop corrections in transient constant-roll inflation [CEA]

Posted on by

http://arxiv.org/abs/2303.16035


In canonical single-field inflation, the production of primordial black holes (PBH) requires a transient violation of the slow-roll condition. The transient ultra slow-roll inflation is an example of such scenario, and more generally, one can consider the transient constant-roll inflation. We investigate the squeezed bispectrum in the transient constant-roll inflation, and find that the Maldacena’s consistency relation holds for a sufficiently long-wavelength mode, whereas it is violated for modes around the peak scale for the non-attractor case. We also demonstrate how the one-loop corrections are modified compared to the case of the transient ultra slow-roll inflation, focusing on representative one-loop terms orgiginating from a time derivative of the second slow-roll parameter in the cubic action. We find that the perturbativity requirement on those terms does not rule out the production of PBH from the transient constant-roll inflation. Therefore, it is a simple counterexample of the recently claimed no-go theorem of PBH production from single-field inflation.

Read this paper on arXiv…

H. Motohashi and Y. Tada
Wed, 29 Mar 23
46/73

Comments: 26 pages, 14 figures

The galaxy-halo connection of DESI luminous red galaxies with subhalo abundance matching [CEA]

Posted on by

http://arxiv.org/abs/2303.16096


We use subhalo abundance and age distribution matching to create magnitude-limited mock galaxy catalogs at $z\sim0.43$, $0.52$, and $0.63$ with $z$-band and $3.4$ micron $W1$-band absolute magnitudes and ${r-z}$ and ${r-W1}$ colors. From these magnitude-limited mocks we select mock luminous red galaxy (LRG) samples according to the $(r-z)$-based (optical) and $(r-W1)$-based (infrared) selection criteria for the LRG sample of the Dark Energy Spectroscopic Instrument (DESI) Survey. Our models reproduce the number densities, luminosity functions, color distributions, and projected clustering of the DESI Legacy Surveys that are the basis for DESI LRG target selection. We predict the halo occupation statistics of both optical and IR DESI LRGs at fixed cosmology, and assess the differences between the two LRG samples. We find that IR-based SHAM modeling represents the differences between the optical and IR LRG populations better than using the $z$-band, and that age distribution matching overpredicts the clustering of LRGs, implying that galaxy color is uncorrelated with halo age in the LRG regime. Both the optical and IR DESI LRG target selections exclude some of the most luminous galaxies that would appear to be LRGs based on their position on the red sequence in optical color-magnitude space. Both selections also yield populations with a non-trivial LRG-halo connection that does not reach unity for the most massive halos. We find the IR selection achieves greater completeness ($\gtrsim 90\%$) than the optical selection across all redshift bins studied.

Read this paper on arXiv…

A. Berti, K. Dawson and W. Dominguez
Wed, 29 Mar 23
65/73

Comments: 20 pages, 14 figures, submitted to ApJ

Revisiting progenitor-age dependence of type Ia supernova luminosity standardization process [CEA]

Posted on by

http://arxiv.org/abs/2303.15267


Much of the research in supernova cosmology is based on an assumption that the peak luminosity of type Ia supernovae (SNe Ia), after a standardization process, is independent of the galactic environment. A series of recent studies suggested that there is a significant correlation between the standardized luminosity and the progenitor age of SNe Ia. The correlation found in the most recent work by Lee et al. is strong enough to explain the extra dimming of distant SNe Ia, and therefore casts doubts on the direct evidence of cosmic acceleration. The present work improves the previous work by incorporating the uncertainties of progenitor ages, which were ignored in Lee et al., into a fully Bayesian inference framework. We find a weaker dependence of supernova standardized luminosity on the progenitor age, but the detection of correlation remains significant (3.3$\sigma$). Assuming that such correlation can be extended to high redshift and applying it to the Pantheon SN Ia data set, we find that the correlation cannot be the primary cause of the observed extra dimming of distant SNe Ia. Further more, we use the PAge formalism, which is a good approximation to many dark energy and modified gravity models, to do a model comparison. The concordance Lambda cold dark matter model remains a good fit when the progenitor-age dependence of SN Ia luminosity is corrected. The best-fit parameters, however, are in $\sim 2\sigma$ tension with the standard values inferred from cosmic microwave background observations.

Read this paper on arXiv…

J. Wang, Z. Huang and L. Huang
Tue, 28 Mar 23
10/81

Comments: 5 pages, 4 figures, 1 tables

Strengthening extended Gravity constraints with combined systems:\\ \texorpdfstring{$f(R)$}{} bounds from Cosmology and the Galactic Center [CEA]

Posted on by

http://arxiv.org/abs/2303.15040


MOdified Gravity (MoG)) is widely constrained in different astrophysical and astronomical systems. Since these different systems are based on different scales it is not trivial to get a combined constraint that is based on different phenomenology. Here, for the first time (to the best of our knowledge), we combine constraints for MoG from late time Cosmology and the orbital motion of the stars around the galactic center. MoG give different potentials that are tested directly in the galactic center. The cosmological data set includes the type Ia supernova and baryon acoustic oscillations. For the galactic star center data set we use the published orbital measurements of the S2 star. The constraints on the universal parameter $\beta$ from the combined system give: $\beta_{HS}=0.154 \pm 0.109$ for the Hu-Sawicki model, while $\beta_{St}= 0.309 \pm 0.19 $ for the Starobinsky model. These results improve on the cosmological results we obtain. The results show that {{\it combined constraint}} from different systems yields a stronger constraint for different theories under consideration. Future measurements from the galactic center and from cosmology will give better constraints on MoG.

Read this paper on arXiv…

D. Benisty, J. Mifsud, J. Said, et. al.
Tue, 28 Mar 23
12/81

Comments: 8 pages, 2 figures

Warm dark matter constraints from the JWST [CEA]

Posted on by

http://arxiv.org/abs/2303.14239


Warm Dark Matter (WDM) particles with masses ($\sim$ kilo electronvolt) offer an attractive solution to the small-scale issues faced by the Cold Dark Matter (CDM) paradigm. The delay of structure formation in WDM models and the associated dearth of low-mass systems at high-redshifts makes this an ideal time to revisit WDM constraints in light of the unprecedented data-sets from the James Webb Space Telescope (JWST). Developing a phenomenological model based on the halo mass functions in CDM and WDM models, we calculate high-redshift ($z \gt 6$) the stellar mass functions (SMF) and the associated stellar mass density (SMD) and the maximum stellar mass allowed in a given volume. We find that: (i) WDM as light as 1.5 keV is already disfavoured by the low-mass end of the SMF (stellar mass $M_* \sim 10^7 \rm{M_\odot}$) although caution must be exerted given the impact of lensing uncertainties; (ii) 1.5 keV WDM models predict SMD values that show a steep decrease from $10^{8.8}$ to $10^{2} ~{\rm M_\odot ~cMpc^{-3}}$ from $z \sim 4$ to 17 for $M_* \gt 10^8 \rm{M_\odot}$; (iii) the 1.5 keV WDM model predicts a sharp and earlier cut-off in the maximum stellar masses for a given number density (or volume) as compared to CDM or heavier WDM models. For example, with a number density of $10^{-3} \rm {cMpc^{-3}}$, 1.5 (3) KeV WDM models do not predict bound objects at $z \gt 12$ (18). Forthcoming JWST observations of multiple blank fields can therefore be used as a strong probe of WDM at an epoch inaccessible by other means.

Read this paper on arXiv…

P. Dayal and S. Giri
Tue, 28 Mar 23
20/81

Comments: Submitted to MNRAS; comments welcome

Investigating the turbulent hot gas in X-COP galaxy clusters [CEA]

Posted on by

http://arxiv.org/abs/2303.15102


Turbulent processes at work in the intracluster medium perturb this environment, displacing gas, and creating local density fluctuations that can be quantified via X-ray surface brightness fluctuation analyses. Improved knowledge of these phenomena would allow for a better determination of the mass of galaxy clusters, as well as a better understanding of their dynamic assembly. In this work, we aim to set constraints on the structure of turbulence using X-ray surface brightness fluctuations. We seek to consider the stochastic nature of this observable and to constrain the structure of the underlying power spectrum. We propose a new Bayesian approach, relying on simulation-based inference to account for the whole error budget. We used the X-COP cluster sample to individually constrain the power spectrum in four regions and within $R_{500}$. We spread the analysis on the 12 systems to alleviate the sample variance. We then interpreted the density fluctuations as the result of either gas clumping or turbulence. For each cluster considered individually, the normalisation of density fluctuations correlates positively with the Zernike moment and centroid shift, but negatively with the concentration and the Gini coefficient. The spectral index within $R_{500}$ and evaluated over all clusters is consistent with a Kolmogorov cascade. The normalisation of density fluctuations, when interpreted in terms of clumping, is consistent within $0.5 R_{500}$ with the literature results and numerical simulations; however, it is higher between 0.5 and $1 R_{500}$. Conversely, when interpreted on the basis of turbulence, we deduce a non-thermal pressure profile that is lower than the predictions of the simulations within 0.5 $R_{500}$, but still in agreement in the outer regions. We explain these results by the presence of central structural residues that are remnants of the dynamic assembly of the clusters.

Read this paper on arXiv…

S. Dupourqué, N. Clerc, E. Pointecouteau, et. al.
Tue, 28 Mar 23
30/81

Comments: Accepted for publication in A&A. Abstract slightly abridged for arXiv