Article
Astronomy & Astrophysics
T. Lucas Makinen, Lachlan Lancaster, Francisco Villaescusa-Navarro, Peter Melchior, Shirley Ho, Laurence Perreault-Levasseur, David N. Spergel
Summary: A deep convolutional neural network (CNN) with UNet architecture is used to effectively separate cosmic neutral hydrogen (HI) signals and foreground contaminants in 21 cm intensity mapping observations. The cleaned maps recover cosmological clustering amplitude and phase accurately, showing significant improvement compared to standard Principal Component Analysis (PCA) methods.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Joseph DeRose, Shi-Fan Chen, Nickolas Kokron, Martin White
Summary: Numerical simulations in cosmology require trade-offs between volume, resolution, and run-time, leading to sample variance in predictions of ensemble-average quantities. We extend the technique of Zel'dovich control variates to reduce the sample variance in measurements of 2-point statistics of biased tracers in redshift space. This allows improved predictions for the clustering of astronomical objects at very modest computational expense.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Francesca Lepori, Sebastian Schulz, Julian Adamek, Ruth Durrer
Summary: We present for the first time halo number counts and their two-point statistics extracted from relativistic N-body simulations. The halo catalogues are built from the relativistic N-body code gevolution, and the observed positions and redshifts of the sources are computed using a non-perturbative ray-tracing method. We investigate the validity and limitations of linear bias prescription and test a second-order perturbative bias expansion for angular statistics. We also extract the cross-correlation of halo number counts and lensing convergence, finding consistent linear bias estimates and the importance of considering magnification effects.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
James M. Sullivan, Uros Seljak, Sukhdeep Singh
Summary: The updated Halo Zeldovich Perturbation Theory (HZPT) model provides an analytic and accurate description of the two-point statistics of dark matter on nonlinear scales, with applications to halo and galaxy clustering as well as galaxy-matter cross-correlation.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Dan Pryer, Robert E. Smith, Robin Booth, Chris Blake, Alexander Eggemeier, Jon Loveday
Summary: The study derives expressions for the galaxy power spectrum convolved by survey window in real space, considering the geometric lightcone effect for full sky and deep redshift surveys. It investigates the impact of using the standard mean redshift approximation, showing both overall amplitude suppression and scale-dependent error compared to the 'true' spectrum. However, it also demonstrates that accurate approximation to the full model can be achieved by carefully choosing an 'effective fixed-time' within a certain range of scales.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Marcel Schmittfull, Marko Simonovic, Mikhail M. Ivanov, Oliver H. E. Philcox, Matias Zaldarriaga
Summary: An analytical forward model based on perturbation theory was developed to predict the redshift-space galaxy overdensity, finding residual noise characteristics in simulated galaxy density. Furthermore, comparison of galaxy velocities revealed that about 10% of galaxies contribute to half of the rms velocity residual in the simulated galaxy sample.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Roy Maartens, Sheean Jolicoeur, Obinna Umeh, Eline M. De Weerd, Chris Clarkson
Summary: Next-generation galaxy and 21cm intensity mapping surveys will rely on high-precision measurements of primordial non-Gaussianity using a combination of power spectrum and bispectrum. Theoretical precision at the same level is essential for these measurements. Incorporating a consistent general relativistic model of galaxy bias at second order extends the theoretical understanding of the galaxy bispectrum. The influence of primordial non-Gaussianity on the bispectrum goes beyond galaxy bias and dark matter density, and includes effects from redshift-space distortions.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
L. Raul Abramo, Joao Vitor Dinarte Ferri, Ian Lucas Tashiro, Arthur Loureiro
Summary: This paper presents a method to predict the constraining power of galaxy surveys using the multi-tracer Fisher matrix based on angular power spectra in the linear regime of structure formation, avoiding the impracticality of deriving the Fisher matrix from numerically evaluated covariance matrices.
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
Sheean Jolicoeur, Roy Maartens, Eline M. De Weerd, Obinna Umeh, Chris Clarkson, Stefano Camera
Summary: The study investigates the detectability of first-order relativistic effects in future 21cm intensity mapping surveys, finding that the imaginary contribution of the relativistic signal in the bispectrum increases the detection possibility, albeit typically with a lower signal-to-noise compared to Hα galaxy surveys, due to foreground and telescope beam effects.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Byeonghee Yu, Uros Seljak, Yin Li, Sukhdeep Singh
Summary: We present growth of structure constraints from the cosmological analysis of the power spectrum multipoles of SDSS-III BOSS DR12 galaxies. We use a galaxy power spectrum model that decomposes galaxies into halo mass bins and combines perturbation theory and halo model to model halo clustering. By constraining a single parameter f sigma 8 to Planck+BAO prior, we reduce the effects of prior volume and mismodeling. Our analysis yields tight constraints on f sigma 8 and discusses the sensitivity of cosmological parameter estimation to various factors.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Pierre Zhang, Yifu Cai
Summary: The study re-analyzed the full shape of the BOSS galaxy two-point function within Lambda-CDM, with results constraining various cosmological parameters. The effect of redshift selection on the results was discussed, emphasizing the importance of systematic assessments for ongoing and future large-volume surveys.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Andrej Obuljen, Will J. Percival
Summary: This study explores the impact of variations in galaxy-pair effective redshift on large-scale clustering in galaxy surveys, finding that surveys spanning a large redshift range have different effective redshifts depending on pair separation and angle, potentially resulting in scale-dependent clustering anisotropy. The effect is demonstrated on the eBOSS DR16 Quasar sample, showing a negligible impact on monopole but a significant tilt in quadrupole and hexadecapole measurements. Strategies for mitigating this effect are discussed.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Henry S. Grasshorn Gebhardt, Olivier Dore
Summary: In this paper, a custom eigenbasis adapted to any particular survey geometry is derived to retain all information on the diagonal of the 2-point function. It results in a diagonal 2-point function with simple shot noise and a diagonal covariance matrix in the case of a Gaussian random field. The derived basis is used to construct a 3D spherical Fourier-Bessel power spectrum estimator assuming a survey geometry that is separable in the angular and radial directions.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Florian Beutler, Patrick McDonald
Summary: Recent developments in galaxy redshift surveys have led to the proposal of a matrix-based analysis framework for galaxy power spectrum multipoles, providing deconvolved power spectrum results for several datasets. The use of deconvolved power spectrum multipoles allows for a data analysis independent of survey-specific aspects, such as the window function. This alternative analysis method has been shown to yield similar results to standard analysis in the case of the BOSS dataset, with various analysis components and a Python toolbox provided for convenience.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(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
Martin White, Rongpu Zhou, Joseph DeRose, Simone Ferraro, Shi-Fan Chen, Nickolas Kokron, Stephen Bailey, David Brooks, Juan Garcia-Bellido, Julien Guy, Klaus Honscheid, Robert Kehoe, Anthony Kremin, Michael Levi, Nathalie Palanque-Delabrouille, Claire Poppett, David Schlegel, Gregory Tarle
Summary: Using luminous red galaxies selected from imaging surveys for targeting by the Dark Energy Spectroscopic Instrument (DESI) in combination with CMB lensing maps from the Planck collaboration, researchers probed the amplitude of large-scale structure over 0.4 <= z <= 1. Their findings suggest a slower growth of structure at low redshift than model predictions, with only modest significance.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Alex Krolewski, Simone Ferraro, Martin White
Summary: Recent lensing measurements at low redshifts suggest that the amplitude of lensing in the universe may be lower than predicted by the Lambda CDM model based on Planck CMB data. By analyzing the auto-and cross-correlation signal of unWISE galaxies and Planck CMB lensing maps, cosmological parameters at low redshifts have been inferred, showing tensions with the CMB predictions. The combination of blue, green, and red unWISE samples gives a value of S-8 = 0.784 +/- 0.015, consistent with other low-redshift lensing measurements and in tension with the CMB predictions from Planck.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Noah Sailer, Emanuele Castorina, Simone Ferraro, Martin White
Summary: By using a Fisher matrix formalism based on recent advances in Lagrangian perturbation theory, constraints for future spectroscopic and 21-cm surveys on the standard cosmological model and its extensions were forecasted and compared with those achievable by current or near-future surveys, such as DESI and Euclid, under the same forecasting formalism. Additionally, comparisons were made between the formalism used and traditional linear methods.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Shi-Fan Chen, Zvonimir Vlah, Martin White
Summary: A new method for analyzing the pre-and post-reconstruction galaxy two-point functions of the BOSS survey is presented. The post-reconstruction correlation function accurately measures the distance-redshift relation and expansion history, while the pre-reconstruction power spectrum multipoles constrain the broad-band shape and rate-of-growth of large-scale structure. The technique uses Lagrangian perturbation theory to directly work with the measured data at the level of two-point functions without approximations. Combining galaxies across the full redshift range and both hemispheres, constraints on Omega(m), H-0, and sigma(8) are obtained that are consistent with the Planck primary CMB anisotropy data and recent cosmic shear surveys.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Joseph DeRose, Shi-Fan Chen, Martin White, Nickolas Kokron
Summary: We use neural networks to accelerate the calculation of power spectra for galaxy clustering and weak gravitational lensing analysis. By constructing neural network-based surrogate models, we achieve high accuracy over a broad range of scales and a computation speed 1000 times faster than traditional methods. The release of these surrogate models will facilitate rapid iteration on analysis settings, which is essential for complex large-scale structure analyses.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Zhejie Ding, Chia-Hsun Chuang, Yu Yu, Lehman H. Garrison, Adrian E. Bayer, Yu Feng, Chirag Modi, Daniel J. Eisenstein, Martin White, Andrei Variu, Cheng Zhao, Hanyu Zhang, Jennifer Meneses Rizo, David Brooks, Kyle Dawson, Peter Doel, Enrique Gaztanaga, Robert Kehoe, Alex Krolewski, Martin Landriau, Nathalie Palanque-Delabrouille, Claire Poppett
Summary: DESI aims to map the Universe with a large and precise three-dimensional map, using high-resolution simulations like ABACUSSUMMIT for validation. The CARPool method is proposed for high statistical precision using accurate and approximate simulations, combined with fast quasi-N-body solvers.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Nickolas Kokron, Joseph DeRose, Shi-Fan Chen, Martin White, Risa H. Wechsler
Summary: This study investigates the stochastic properties of typical red galaxy samples in a controlled numerical environment. Using halo occupation distribution (HOD) modelling and Second-order Hybrid Effective Field Theory (HEFT), the researchers directly measure and compare the stochastic power spectra of these samples, and apply the results in cosmological analyses.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Shi-Fan Chen, Martin White, Joseph DeRose, Nickolas Kokron
Summary: We propose a formalism for jointly fitting pre-and post-reconstruction redshift-space clustering, baryon acoustic oscillations, and gravitational lensing. We analyze clustering measured by the Baryon Oscillation Spectroscopic Survey in combination with CMB lensing measured by Planck. The results provide valuable constraints on various cosmological parameters.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Nickolas Kokron, Shi-Fan Chen, Martin White, Joseph DeRose, Mark Maus
Summary: Simulations are essential for accurate modeling of observables in galaxy surveys, but can be expensive when a large dynamic range is required. This study presents a method that combines Lagrangian perturbation theory models with N-body simulations to reduce the effects of finite computational volume on the prediction of ensemble average properties in the simulations. By utilizing the correlation between Zel'dovich displacements and the final density field, the method achieves significant reductions in sample variance for power spectrum or correlation function estimation. It has the potential to extend simulations to larger scales and improve measurements of statistics in simulations that are limited to small volumes.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Noah Sailer, Shi-Fan Chen, Martin White
Summary: The optical depth tau is an important parameter in cosmology, but it is least well determined. Future reionization experiments using symmetries-based bias expansion could provide tight constraints on tau. These experiments would require measuring anisotropies in the power spectrum on large scales. Ionization evolution models can help in constraining the timing and duration of reionization, and hence tau, through next-generation 21 cm surveys.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
A. Amon, N. C. Robertson, H. Miyatake, C. Heymans, M. White, J. DeRose, S. Yuan, R. H. Wechsler, T. N. Varga, S. Bocquet, A. Dvornik, S. More, A. J. Ross, H. Hoekstra, A. Alarcon, M. Asgari, J. Blazek, A. Campos, R. Chen, A. Choi, M. Crocce, H. T. Diehl, C. Doux, K. Eckert, J. Elvin-Poole, S. Everett, A. Ferte, M. Gatti, G. Giannini, D. Gruen, R. A. Gruendl, W. G. Hartley, K. Herner, H. Hildebrandt, S. Huang, E. M. Huff, B. Joachimi, S. Lee, N. MacCrann, J. Myles, A. Navarro-Alsina, T. Nishimichi, J. Prat, L. F. Secco, I Sevilla-Noarbe, E. Sheldon, T. Shin, T. Troster, M. A. Troxel, I Tutusaus, A. H. Wright, B. Yin, M. Aguena, S. Allam, J. Annis, D. Bacon, M. Bilicki, D. Brooks, D. L. Burke, A. Carnero Rosell, J. Carretero, F. J. Castander, R. Cawthon, M. Costanzi, L. N. da Costa, M. E. S. Pereira, J. de Jong, J. De Vicente, S. Desai, J. P. Dietrich, P. Doel, I Ferrero, J. Frieman, J. Garcia-Bellido, D. W. Gerdes, J. Gschwend, G. Gutierrez, S. R. Hinton, D. L. Hollowood, K. Honscheid, D. Huterer, A. Kannawadi, K. Kuehn, N. Kuropatkin, O. Lahav, M. Lima, M. A. G. Maia, J. L. Marshall, F. Menanteau, R. Miquel, J. J. Mohr, R. Morgan, J. Muir, F. Paz-Chinchon, A. Pieres, A. A. Plazas Malagon, A. Porredon, M. Rodriguez-Monroy, A. Roodman, E. Sanchez, S. Serrano, H. Shan, E. Suchyta, M. E. C. Swanson, G. Tarle, D. Thomas, C. To, Y. Zhang
Summary: We evaluate the consistency between lensing and clustering by combining measurements from Baryon Oscillation Spectroscopic Survey, DES Year 3, HSC Year 1, and KiDS-1000. Good agreement is found between these lensing data sets. Two fixed cosmologies, Planck and Lensing cosmology, are used to fit the data, and both provide an acceptable fit at large scales. However, uncertainties in baryon feedback and assembly bias hinder the full utilization of small-scale measurements.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Benjamin Horowitz, Khee-Gan Lee, Metin Ata, Thomas Mueller, Alex Krolewski, J. Xavier Prochaska, Joseph F. F. Hennawi, Martin White, David Schlegel, R. Michael Rich, Peter E. Nugent, Nao Suzuki, Daichi Kashino, Anton M. M. Koekemoer, Brian C. C. Lemaux
Summary: This study presents the second data release of the COSMOS Ly alpha Mapping And Tomography Observations Survey, which uses Lα absorption to study neutral hydrogen in the intergalactic medium. The reconstructed 3D maps reveal the detailed cosmic web consisting of voids, sheets, filaments, and nodes. The data is publicly available for further exploration and qualitative comparisons.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2022)
Article
Astronomy & Astrophysics
Joseph DeRose, Shi-Fan Chen, Nickolas Kokron, Martin White
Summary: Numerical simulations in cosmology require trade-offs between volume, resolution, and run-time, leading to sample variance in predictions of ensemble-average quantities. We extend the technique of Zel'dovich control variates to reduce the sample variance in measurements of 2-point statistics of biased tracers in redshift space. This allows improved predictions for the clustering of astronomical objects at very modest computational expense.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Emmanuel Schaan, Martin White
Summary: Line intensity mapping (LIM) is a rapidly emerging technique for constraining cosmology and galaxy formation using multi-frequency, low angular resolution maps. This technique relies on cross-correlations of line intensity maps to reveal astrophysical properties of the interstellar medium. The study clarifies the sources of luminosity scatter or line noise in LIM, and demonstrates that the effective number density of halos can in some cases exceed that of galaxies.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)