Article
Astronomy & Astrophysics
Shang Li, Ji-Ping Dai, Xiu-Hui Tan, Yang-Jie Yan, Jun-Qing Xia
Summary: The bounce scenario in cosmology is a research topic that addresses the singularity problem and trans-Planckian issue left by the standard inflationary theory. In this work, the authors extend the analysis to large-scale structure measurements and find that the model parameters can be constrained effectively. The constraints become even stronger when combined with the measurements from the Planck satellite.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Cristhian Garcia, Camilo Santa, Antonio Enea Romano
Summary: This article introduces the use of convolutional neural networks to solve the inversion problem of the large-scale structure of the Universe. By observing the luminosity distance of Supernovae Ia, the researchers can reconstruct the large-scale structure. The results show that the velocity field inversion is more accurate than the density field.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Ginevra Favole, Benjamin R. Granett, Javier Silva Lafaurie, Domenico Sapone
Summary: The study investigates the jackknife method for internal covariance estimation in large-scale structure surveys, exploring the impact of jackknife size and number of resamplings on the precision of the covariance estimate and errors in cosmological parameters. Results show that the baryon acoustic scale error estimate is independent of the jackknife scale, while the shift parameter a exhibits variations in error estimates from different datasets.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Rafael Garcia, Eduardo Rozo, Matthew R. Becker, Surhud More
Summary: The proposed model integrates halo exclusion and redefines halo boundary in a flexible way, leading to successful description of the halo-mass correlation function within a certain range. The features of the model, including scale-dependent biasing and a transition radius, contribute to a more accurate representation of haloes' behavior in tracing mass.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Naonori S. Sugiyama, Daisuke Yamauchi, Tsutomu Kobayashi, Tomohiro Fujita, Shun Arai, Shin'ichi Hirano, Shun Saito, Florian Beutler, Hee-Jong Seo
Summary: For the first time, we have conducted an observational test of the consistency relation for the large-scale structure (LSS) of the Universe by jointly analyzing the anisotropic two-and three-point correlation functions (2PCF and 3PCF) of galaxies. Using the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12, we found no violation of the LSS consistency relation in our analysis within the statistical errors. Our analysis opens up a new observational window to test fundamental physics using anisotropic higher-order correlation functions of galaxy clustering.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Sownak Bose, Boryana Hadzhiyska, Monica Barrera, Ana Maria Delgado, Fulvio Ferlito, Carlos Frenk, Cesar Hernandez-Aguayo, Lars Hernquist, Rahul Kannan, Ruediger Pakmor, Volker Springel, Simon D. M. White
Summary: Modern redshift surveys are mapping the distribution of galaxies on enormous distance scales. However, current hydrodynamical simulations cannot reach the volumes needed for upcoming surveys. A new, large volume hydrodynamical simulation called MillenniumTNG (MTNG) is able to accurately reproduce the observed clustering of galaxies, but there are discrepancies when separated by color. This is due to the quenching of satellite galaxies in the model.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Ivelin Georgiev, Garrelt Mellema, Sambit K. Giri, Rajesh Mondal
Summary: This study investigates the evolution of the 21-cm power spectrum through numerical and semi-numerical simulations, revealing that the large-scale signal is related to the cosmological density field, while the small-scale power spectrum is influenced by the astrophysics of reionization.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Fulvio Melia, Qingbo Ma, Jun-Jie Wei, Bo Yu
Summary: This paper investigates potential anomalies in the fluctuation spectrum of the cosmic microwave background temperature, suggesting that the cutoff in the primordial power spectrum may explain both the low level of correlation at large angles and missing power in the low multipole moments of the angular power spectrum. The study confirms that introducing this cutoff does not affect the overall consistency between Planck-ΛCDM prediction and measurements at l30.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Thomas Kite, Jens Chluba, Andrea Ravenni, Subodh P. Patil
Summary: The researchers used numerical methods to explore the energy spectrum characteristics of the primordial gravitational wave background, discussing the effects of different eras in the early universe and their importance in cosmological parameters. Numerical analysis can reveal potential errors in previous literature and describe the effects of gravitational wave backgrounds at different scales.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Boryana Hadzhiyska, Sonya Liu, Rachel S. Somerville, Austen Gabrielpillai, Sownak Bose, Daniel Eisenstein, Lars Hernquist
Summary: In this study, two galaxy models (Illustris'ING and SC-SAM) were compared for their predictions on large scale structure observables for stellar mass selected samples at z=0. The models show good agreement in two-point clustering and galaxy assembly bias, but differences in areas such as halo gas content correlation with environment and occupancy predictions for low-mass haloes. Higher order statistics help accurately describe the galaxy distribution and differentiate between models showing similar behavior in two-point statistics. SAMs are suggested as a promising method for generating mock catalogues for future cosmological surveys.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Fulvio Melia
Summary: Studies of the Universe's transition to smoothness based on the Lambda cold dark matter (Lambda CDM) model have found a transition radius of about 300 Mpc. However, observations have shown giant structures extending over scales much larger than expected, suggesting the possibility of new physics. In this paper, the fractal dimension is calculated as a function of distance in the alternative R-h = ct cosmology, showing a smooth transition at about 2.2 Gpc and providing further support for this model.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Eleni Tsaprazi, Jens Jasche, Ariel Goobar, Hiranya Peiris, Igor Andreoni, Michael W. Coughlin, Christoffer U. Fremling, Matthew J. Graham, Mansi Kasliwal, Shri R. Kulkarni, Ashish A. Mahabal, Reed Riddle, Jesper Sollerman, Anastasios Tzanidakis
Summary: The new generation of wide-field time-domain surveys has enabled the study of clustering of supernova host galaxies in the large-scale structure for the first time. The research found that supernovae exhibit high significance clustering and their distribution in the LSS is consistent with that of SDSS galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Konstantinos Tanidis, Stefano Camera
Summary: In this paper, the multitracer technique is applied to harmonic-space power spectra with a likelihood-based approach, surpassing the usual Fisher matrix formalism. A modified version of the CosmoSIS code, including all previously presented add-ons, is released for cosmological parameter estimation. The improvement in parameter constraints enabled by the use of multiple tracers is demonstrated, achieving a 44% enhancement on the 2 sigma upper bound on the sum of neutrino masses.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Cheng-Zong Ruan, Carolina Cuesta-Lazaro, Alexander Eggemeier, Cesar Hernandez-Aguayo, Carlton M. Baugh, Baojiu Li, Francisco Prada
Summary: The upcoming generation of galaxy surveys will allow us to test cosmological models with higher precision. To achieve this, more accurate theoretical predictions are needed. In this study, we investigate the validity of the Skew-T (ST) probability distribution function (PDF) of halo pairwise peculiar velocities in modified gravity cosmologies to improve small-scale predictions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Swati Gavas, Jasjeet Bagla, Nishikanta Khandai, Girish Kulkarni
Summary: In this paper, we investigate the power spectrum dependence of halo mass function through a suite of dark-matter-only N-body simulations. The mass function shows a clear non-universality, and fits for the parameters of the Sheth-Tormen mass function are presented. We also show that the Sheth-Tormen mass function derived from a matched power-law Einstein-de Sitter cosmology provides a better fit to the LCDM mass function.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Shi-Fan Chen, Zvonimir Vlah, Emanuele Castorina, Martin White
Summary: In this study, a method for computing the one-loop 2-point function of biased tracers in redshift space is presented using Lagrangian perturbation theory, with a full resummation of long-wavelength displacements and velocities. The model accurately predicts the power spectrum and correlation function of halos and mock galaxies, including baryon acoustic oscillation signal damping due to bulk galaxy motions. The study also compares this full resummation approach with other techniques and discusses the computation of resulting expressions numerically for efficient computation.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
ChangHoon Hahn, Francisco Villaescusa-Navarro
Summary: This study examines the constraining power of the redshift-space galaxy bispectrum monopole, B-0(g), on cosmological parameters and the information content down to nonlinear scales. The results show that B-0(g) significantly improves the constraints on cosmological parameters, especially for M-nu.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Digvijay Wadekar, Francisco Villaescusa-Navarro, Shirley Ho, Laurence Perreault-Levasseur
Summary: Upcoming 21 cm surveys will map the spatial distribution of cosmic neutral hydrogen, and accurate theoretical predictions are essential. Using convolutional neural networks to find the mapping between matter distribution and Hi yields better results than traditional theoretical models, allowing the generation of 21 cm mocks over large cosmological volumes similar to hydrodynamic simulations.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Francisco Villaescusa-Navarro, Daniel Angles-Alcazar, Shy Genel, David N. Spergel, Rachel S. Somerville, Romeel Dave, Annalisa Pillepich, Lars Hernquist, Dylan Nelson, Paul Torrey, Desika Narayanan, Yin Li, Oliver Philcox, Valentina La Torre, Ana Maria Delgado, Shirley Ho, Sultan Hassan, Blakesley Burkhart, Digvijay Wadekar, Nicholas Battaglia, Gabriella Contardo, Greg L. Bryan
Summary: The CAMELS project consists of 4233 cosmological simulations designed to provide theory predictions for different observables and train machine-learning algorithms. It includes various cosmological and astrophysical models, tracking the evolution of over 100 billion particles and fluid elements, and providing valuable data for studying matter power spectrum and cosmic star formation rate density, among others.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Adrian E. Bayer, Francisco Villaescusa-Navarro, Elena Massara, Jia Liu, David N. Spergel, Licia Verde, Benjamin D. Wandelt, Matteo Viel, Shirley Ho
Summary: By combining different statistical methods and utilizing the Quijote N-body simulations, tighter constraints on cosmological parameters can be obtained. The combination of the nonlinear matter power spectrum, the halo mass function, and the void size function effectively breaks degeneracies and enhances the information content on parameters like neutrino mass.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Lado Samushia, Zachary Slepian, Francisco Villaescusa-Navarro
Summary: This study explores the use of galaxy N-point correlation functions as standard rulers for distance-redshift relationship constraints, demonstrating that reconstruction of the initial density field can offer better constraints than analyzing higher order correlation functions of the non-linear field. Using joint analysis of two and three-point correlation functions can sometimes provide better constraints than those obtained from the initial power spectrum.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Chirag Modi, Martin White, Emanuele Castorina, Anze Slosar
Summary: By adding external galaxy distribution data to the 21-cm surveys, the lost long wavelength modes can be partially recovered. The spectroscopic sample performs better in reconstructing the largest modes, despite having lower number density.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Azadeh Moradinezhad Dizgah, Farnik Nikakhtar, Garrett K. Keating, Emanuele Castorina
Summary: Line intensity mapping is an emerging technique that has the potential to accurately probe signals at different scales and redshifts. By using simulations and modeling, researchers have been able to accurately predict clustering power and stochastic contributions of intensity fluctuations. Furthermore, this technique shows promise in measuring the baryon acoustic oscillations, which has important implications for cosmological studies in the future.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Emanuele Castorina, Enea Di Dio
Summary: Measurements of galaxy clustering in Fourier space provide insights into the early Universe and the effects of Primordial Non Gaussianities. Relativistic effects can complicate the interpretation of data and may diverge in the Infra-Red. This work calculates the ensemble average of a commonly used Fourier space estimator, considering all general relativistic effects. The study finds that once the individual divergent GR terms are taken into account, there is no Infra-Red sensitivity in the observable. Additionally, the importance of GR effects, including lensing magnification, in interpreting the galaxy power spectrum multipoles is investigated, revealing them to be generally small corrections to the leading redshift space distortions term.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Francisco Villaescusa-Navarro, Benjamin D. Wandelt, Daniel Angles-Alcazar, Shy Genel, Jose Manuel Zorrilla Matilla, Shirley Ho, David N. Spergel
Summary: Many studies have found that a wealth of cosmological information can be found on small scales, but there are challenges in utilizing this information due to the lack of an optimal estimator and the uncertain impact of baryonic effects. This work demonstrates that neural networks can achieve the extraction of maximum cosmological information while marginalizing over baryonic effects in simple scenarios, using power spectra and 2D Gaussian density fields as training data.
ASTROPHYSICAL JOURNAL
(2022)
Editorial Material
Astronomy & Astrophysics
Luca Teodori, Kfir Blum, Emanuele Castorina, Marko Simonovic, Yotam Soreq
Summary: In this paper, we discuss the issue of modeling degeneracies in strong lensing measurements of the Hubble parameter H-0. We highlight the importance of considering weak lensing effects associated with different segments of the line of sight, and propose the inclusion of external convergence terms to avoid bias in the inferred value of H-0. We also show that the use of imaging data for multiple strongly-lensed sources cannot fully resolve the mass sheet degeneracy.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Maria Archidiacono, Emanuele Castorina, Diego Redigolo, Ennio Salvioni
Summary: This study initiates the exploration of the cosmology of dark fifth forces, which are new forces acting solely on Dark Matter. It is found that the dark fifth force can be realized by a light scalar coupled to Dark Matter, and it has significant effects on the background cosmology and linear perturbations.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Kevin Pardede, Federico Rizzo, Matteo Biagetti, Emanuele Castorina, Emiliano Sefusatti, Pierluigi Monaco
Summary: A method to perform exact convolution of the model prediction for bispectrum multipoles in redshift space with the survey window function is presented. By extending a widely applied method for power spectrum convolution to bispectrum and utilizing a 2D-FFTlog algorithm, accurate results are obtained.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Elena Giusarma, Mauricio Reyes, Francisco Villaescusa-Navarro, Siyu He, Shirley Ho, ChangHoon Hahn
Summary: Measuring the sum of the three active neutrino masses, M(nu), is a crucial task in modern cosmology. In this study, a deep-learning network ((DM)-M-3) is proposed as a faster and accurate alternative to traditional N-body techniques for generating simulations with massive neutrinos. The results show that our method can generate simulations with a comparable power spectrum within nonlinear scales and is 10,000 times faster than traditional methods.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Pablo Villanueva-Domingo, Francisco Villaescusa-Navarro
Summary: Studying temperature fluctuations in the 21 cm signal is a promising way to explore the universe at high redshifts, but the signal is influenced by cosmology and astrophysical processes. Researchers conducted numerous numerical simulations and trained a convolutional neural network to remove astrophysical effects from the 21 cm maps, generating maps of the underlying matter field.
ASTROPHYSICAL JOURNAL
(2021)
