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Related papers: On fast Generation of Cosmological Random Fields

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We present an algorithm to self-consistently generate mock weak gravitational lensing convergence fields and galaxy distributions in redshift space. We generate three-dimensional cosmic density fields that follow a log-normal distribution,…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-14 Ryu Makiya , Issha Kayo , Eiichiro Komatsu

We introduce a deep generative framework for high-dimensional Bayesian inference that enables efficient posterior sampling. As telescopes and simulations rapidly expand the volume and resolution of astrophysical data, fast simulation-based…

Instrumentation and Methods for Astrophysics · Physics 2026-03-06 Hadi Sotoudeh , Pablo Lemos , Laurence Perreault-Levasseur

An attractive and simple hypothesis for the formation of large-scale structure is that it developed by gravitational instability from primordial fluctuations with an initially Gaussian probability distribution. Non-linear gravitational…

Astrophysics · Physics 2015-06-24 Ewa Luiza Lokas , Roman Juszkiewicz , David Weinberg , Francois Bouchet

The quasi-2D electrostatic systems, characterized by periodicity in two dimensions with a free third dimension, have garnered significant interest in many fields. We apply the sum-of-Gaussians (SOG) approximation to the Laplace kernel,…

Numerical Analysis · Mathematics 2024-12-09 Xuanzhao Gao , Shidong Jiang , Jiuyang Liang , Zhenli Xu , Qi Zhou

Though Gaussian graphical models have been widely used in many scientific fields, relatively limited progress has been made to link graph structures to external covariates. We propose a Gaussian graphical regression model, which regresses…

Methodology · Statistics 2022-02-01 Jingfei Zhang , Yi Li

Galaxy formation and evolution involves a variety of effectively stochastic processes that operate over different timescales. The Extended Regulator model provides an analytic framework for the resulting variability (or `burstiness') in…

Astrophysics of Galaxies · Physics 2024-02-14 Kartheik G. Iyer , Joshua S. Speagle , Neven Caplar , John C. Forbes , Eric Gawiser , Joel Leja , Sandro Tacchella

Non-Gaussianity in the cosmic microwave background and the large-scale structure of galaxies provides an increasingly powerful probe of the universe. I implement an algorithm to generate realisations of fields that possess an arbitrary…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Iain A. Brown

On-going or soon to come cosmological large-scale structure surveys such as DESI, SPHEREx, Euclid, or the High-Latitude Spectroscopic Survey of the Nancy Grace Roman Space Telescope promise unprecedented measurement of the clustering of…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-02 Brandon Khek , Henry S. Grasshorn Gebhardt , Olivier Doré

The covariance matrix of the matter power spectrum is a key element of the statistical analysis of galaxy clustering data. Independent realisations of observational measurements can be used to sample the covariance, nevertheless statistical…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-14 Linda Blot , Pier Stefano Corasaniti , Luca Amendola , Thomas D. Kitching

Generative models are a promising tool to produce cosmological simulations but face significant challenges in scalability, physical consistency, and adherence to domain symmetries, limiting their utility as alternatives to $N$-body…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-26 Diana-Alexandra Onutu , Yue Zhao , Joaquin Vanschoren , Vlado Menkovski

We present the exact joint likelihood of pseudo-$C_\ell$ power spectrum estimates measured from an arbitrary number of Gaussian cosmological fields. Our method is applicable to both spin-0 fields and spin-2 fields, including a mixture of…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-09 Robin E. Upham , Lee Whittaker , Michael L. Brown

In order to prepare for the upcoming wide-field cosmological surveys, large simulations of the Universe with realistic galaxy populations are required. In particular, the tendency of galaxies to naturally align towards overdensities, an…

We extend field-level inference to jointly constrain the cosmological parameters $\{A,\omega_{\rm cdm},H_0\}$, in both real and redshift space. Our analyses are based on mock data generated using a perturbative forward model, with noise…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-25 Kazuyuki Akitsu , Marko Simonović , Shi-Fan Chen , Giovanni Cabass , Matias Zaldarriaga

Cosmologists aim to model the evolution of initially low amplitude Gaussian density fluctuations into the highly non-linear "cosmic web" of galaxies and clusters. They aim to compare simulations of this structure formation process with…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-05 Renan Alves de Oliveira , Yin Li , Francisco Villaescusa-Navarro , Shirley Ho , David N. Spergel

Weak gravitational lensing requires precise measurements of galaxy shapes and therefore an accurate knowledge of the PSF model. The latter can be a source of systematics that affect the shear two-point correlation function. A key stake of…

Gravitational lensing allows to quantify the angular distribution of the convergence field around clusters of galaxies to constrain their connectivity to the cosmic web. We describe in this paper the corresponding theory in Lagrangian space…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-20 Sandrine Codis , Raphael Gavazzi , Christophe Pichon , Celine Gouin

Building upon the recent pioneering work by Mazenko and by Das and Mazenko, we develop a microscopic, non-equilibrium, statistical field theory for initially correlated canonical ensembles of classical microscopic particles obeying…

Statistical Mechanics · Physics 2019-04-08 Matthias Bartelmann , Felix Fabis , Daniel Berg , Elena Kozlikin , Robert Lilow , Celia Viermann

We apply a very simple procedure to construct non-singular cosmological models for flat Friedmann universes filled with minimally coupled scalar fields or by tachyon Born-Infeld-type fields. Remarkably, for the minimally coupled scalar…

General Relativity and Quantum Cosmology · Physics 2024-03-14 Alexander Kamenshchik , Polina Petriakova

Cosmological random fields are often analysed in spherical Fourier-Bessel basis. Compared to the Cartesian Fourier basis this has an advantage of properly taking into account some of the relevant physical processes (redshift-space…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-17 Lado Samushia

Weak gravitational lensing observations probe the spectrum and evolution of density fluctuations and the cosmological parameters which govern them. At low redshifts, the non-linear gravitational evolution of large scale structure produces a…

Astrophysics · Physics 2009-10-31 Asantha Cooray , Wayne Hu