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The growing field of large-scale time domain astronomy requires methods for probabilistic data analysis that are computationally tractable, even with large datasets. Gaussian Processes are a popular class of models used for this purpose…

Instrumentation and Methods for Astrophysics · Physics 2017-11-15 Daniel Foreman-Mackey , Eric Agol , Sivaram Ambikasaran , Ruth Angus

Gaussian random fields are popular models for spatially varying uncertainties, arising for instance in geotechnical engineering, hydrology or image processing. A Gaussian random field is fully characterised by its mean function and…

Numerical Analysis · Mathematics 2019-02-19 Jonas Latz , Marvin Eisenberger , Elisabeth Ullmann

Joint analyses of the large-scale distribution of galaxies, and their motions under the gravitational influence of this density field, allow powerful tests of the cosmological model, including measurement of the growth rate of cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-14 Chris Blake , Ryan J. Turner

The observable universe contains density perturbations on scales larger than any finite volume survey. Perturbations on scales larger than a survey can measure degrade its power to constrain cosmological parameters. The dependence of survey…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-09 Matthew C. Digman , Joseph E. McEwen , Christopher M. Hirata

We demonstrate the capabilities of probabilistic diffusion models to reduce dramatically the computational cost of expensive hydrodynamical simulations to study the relationship between observable baryonic cosmological probes and dark…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-22 Satvik Mishra , Roberto Trotta , Matteo Viel

Field-level inference has emerged as a promising framework to fully harness the cosmological information encoded in next-generation galaxy surveys. It involves performing Bayesian inference to jointly estimate the cosmological parameters…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-19 Hugo Simon , François Lanusse , Arnaud de Mattia

The large-scale structure in cosmology is highly non-Gaussian at late times and small length scales, making it difficult to describe analytically. Parameter inference, data reconstruction, and data generation tasks in cosmology are greatly…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-13 Adam Rouhiainen

Detecting and measuring a non-Gaussian signature of primordial origin in the density field is a major science goal of next-generation galaxy surveys. The signal will permit us to determine primordial physics processes and constrain models…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Adam Andrews , Jens Jasche , Guilhem Lavaux , Fabian Schmidt

Isotropic Gaussian random fields on the sphere are characterized by Karhunen-Lo\`{e}ve expansions with respect to the spherical harmonic functions and the angular power spectrum. The smoothness of the covariance is connected to the decay of…

Probability · Mathematics 2015-10-26 Annika Lang , Christoph Schwab

Upcoming Large Scale Structure surveys aim to achieve an unprecedented level of precision in measuring galaxy clustering. However, accurately modeling these statistics may require theoretical templates that go beyond second-order…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-21 M. Icaza-Lizaola , Yong-Seon Song , Minji Oh , Yi Zheng

We show how to estimate the covariance of the power spectrum of a statistically homogeneous and isotropic density field from a single periodic simulation, by applying a set of weightings to the density field, and by measuring the scatter in…

Astrophysics · Physics 2009-11-11 A. J. S. Hamilton , C. D. Rimes , R. Scoccimarro

Optimal extraction of the non-Gaussian information encoded in the Large-Scale Structure (LSS) of the universe lies at the forefront of modern precision cosmology. We propose achieving this task through the use of the Wavelet Scattering…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-30 Georgios Valogiannis , Cora Dvorkin

(Abridged) I investigate statistical properties of one-dimensional fields in the universe such as the Lyman alpha forest and inverted line-of-sight densities. Because of gravitational clustering, the cosmic density field is already quite…

Astrophysics · Physics 2007-05-23 Hu Zhan

Cosmological probes pose an inverse problem where the measurement result is obtained through observations, and the objective is to infer values of model parameters which characterize the underlying physical system -- our Universe. Modern…

Instrumentation and Methods for Astrophysics · Physics 2019-05-21 Timur Takhtaganov , Zarija Lukic , Juliane Mueller , Dmitriy Morozov

We propose a novel discrete method of constructing Gaussian Random Fields (GRF) based on a combination of modified spectral representations, Fourier and Blob. The method is intended for Direct Numerical Simulations of the V-Langevin…

Computational Physics · Physics 2020-06-22 D. I. Palade , M. Vlad

I present a method for the fast convolution of a model galaxy profile by a point-spread function (PSF) model represented as a pixel grid. The method relies upon three observations: First, most simple radial galaxy profiles of common…

Instrumentation and Methods for Astrophysics · Physics 2021-01-01 Dustin Lang

The disconnected part of the power spectrum covariance matrix (also known as the "Gaussian" covariance) is the dominant contribution on large scales for galaxy clustering and weak lensing datasets. The presence of a complicated sky mask…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-02 Carlos García-García , David Alonso , Emilio Bellini

The peculiar velocities of galaxies cause their redshift-space clustering to depend on the angle to the line-of-sight, providing a key test of gravitational physics on cosmological scales. These effects may be described using a multipole…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-25 Chris Blake , Paul Carter , Jun Koda

Cosmological simulations of galaxy formation are limited by finite computational resources. We draw from the ongoing rapid advances in Artificial Intelligence (specifically Deep Learning) to address this problem. Neural networks have been…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-10 Yin Li , Yueying Ni , Rupert A. C. Croft , Tiziana Di Matteo , Simeon Bird , Yu Feng

Provided a random realization of the cosmological model, observations of our cosmic neighborhood now allow us to build simulations of the latter down to the non-linear threshold. The resulting local Universe models are thus accurate up to a…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-10 Jenny G. Sorce