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With increasingly large data sets, weak lensing measurements are able to measure cosmological parameters with ever greater precision. However this increased accuracy also places greater demands on the statistical tools used to extract the…

Astrophysics · Physics 2015-05-13 S. Pires , J. -L. Starck , A. Amara , R. Teyssier , A. Refregier , J. Fadili

Gaussian processes (GPs) are a popular model for spatially referenced data and allow descriptive statements, predictions at new locations, and simulation of new fields. Often a few parameters are sufficient to parameterize the covariance…

Machine Learning · Statistics 2021-01-01 Florian Gerber , Douglas W. Nychka

Diffusion and flow-based generative models have shown strong potential for image restoration. However, image denoising under unknown and varying noise conditions remains challenging, because the learned vector fields may become inconsistent…

Computer Vision and Pattern Recognition · Computer Science 2026-04-06 Jigang Duan , Genwei Ma , Xu Jiang , Wenfeng Xu , Ping Yang , Xing Zhao

Convolutional Neural Networks (CNN) have recently been demonstrated on synthetic data to improve upon the precision of cosmological inference. In particular they have the potential to yield more precise cosmological constraints from weak…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-17 Janis Fluri , Tomasz Kacprzak , Aurelien Lucchi , Alexandre Refregier , Adam Amara , Thomas Hofmann , Aurel Schneider

Using higher-order statistics to capture cosmological information from weak lensing surveys often requires a transformation of observed shear to a measurement of the convergence signal. This inverse problem is complicated by noise and…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 Nisha Grewal , Joe Zuntz , Tilman Tröster

Density estimation, a central problem in machine learning, can be performed using Normalizing Flows (NFs). NFs comprise a sequence of invertible transformations, that turn a complex target distribution into a simple one, by exploiting the…

Machine Learning · Computer Science 2024-01-04 Massimiliano Patacchiola , Aliaksandra Shysheya , Katja Hofmann , Richard E. Turner

Convolutional Neural Networks (CNNs) have recently been applied to cosmological fields -- weak lensing mass maps and galaxy maps. However, cosmological maps differ in several ways from the vast majority of images that CNNs have been tested…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-05 Kunhao Zhong , Marco Gatti , Bhuvnesh Jain

Normalizing Flows (NFs) describe a class of models that express a complex target distribution as the composition of a series of bijective transformations over a simpler base distribution. By limiting the space of candidate transformations…

Machine Learning · Computer Science 2023-09-11 Keegan Kelly , Lorena Piedras , Sukrit Rao , David Roth

Modeling real-world distributions can often be challenging due to sample data that are subjected to perturbations, e.g., instrumentation errors, or added random noise. Since flow models are typically nonlinear algorithms, they amplify these…

Machine Learning · Computer Science 2022-10-11 Sameera Ramasinghe , Kasun Fernando , Salman Khan , Nick Barnes

In this paper, we show that Minkowski Functionals (MFs) of weak gravitational lensing (WL) convergence maps contain significant non-Gaussian, cosmology-dependent information. To do this, we use a large suite of cosmological ray-tracing…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Jan M. Kratochvil , Eugene A. Lim , Sheng Wang , Zoltan Haiman , Morgan May , Kevin Huffenberger

Focusing on the well motivated aperture mass statistics $\Map$, we study the possibility of constraining cosmological parameters using future space based SNAP class weak lensing missions. Using completely analytical results we construct the…

Astrophysics · Physics 2007-05-23 Dipak Munshi , Patrick Valageas

This paper proposes a general enhancement to the Normalizing Flows (NF) used in neural vocoding. As a case study, we improve expressive speech vocoding with a revamped Parallel Wavenet (PW). Specifically, we propose to extend the affine…

Audio and Speech Processing · Electrical Eng. & Systems 2022-02-17 Adam Gabryś , Yunlong Jiao , Viacheslav Klimkov , Daniel Korzekwa , Roberto Barra-Chicote

Normalizing flows are a class of deep generative models that provide a promising route to sample lattice field theories more efficiently than conventional Monte Carlo simulations. In this work we show that the theoretical framework of…

High Energy Physics - Lattice · Physics 2022-07-07 Michele Caselle , Elia Cellini , Alessandro Nada , Marco Panero

We describe an approximate statistical model for the sample variance distribution of the non-linear matter power spectrum that can be calibrated from limited numbers of simulations. Our model retains the common assumption of a multivariate…

The normalization constraint on probability density poses a significant challenge for solving the Fokker-Planck equation. Normalizing Flow, an invertible generative model leverages the change of variables formula to ensure probability…

Machine Learning · Computer Science 2023-09-28 Feng Liu , Faguo Wu , Xiao Zhang

Normalizing flows are a popular class of models for approximating probability distributions. However, their invertible nature limits their ability to model target distributions whose support have a complex topological structure, such as…

Machine Learning · Statistics 2022-02-25 Vincent Stimper , Bernhard Schölkopf , José Miguel Hernández-Lobato

Normalizing flows can generate complex target distributions and thus show promise in many applications in Bayesian statistics as an alternative or complement to MCMC for sampling posteriors. Since no data set from the target posterior…

Machine Learning · Statistics 2021-07-19 Marylou Gabrié , Grant M. Rotskoff , Eric Vanden-Eijnden

Bayesian inference with computationally expensive likelihood evaluations remains a significant challenge in many scientific domains. We propose normalizing flow regression (NFR), a novel offline inference method for approximating posterior…

Machine Learning · Statistics 2025-04-17 Chengkun Li , Bobby Huggins , Petrus Mikkola , Luigi Acerbi

We present a concept study on weak lensing map reconstruction through the cosmic magnification effect in galaxy number density distribution. We propose a minimal variance linear estimator to minimize both the dominant systematical and…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-16 Xinjuan Yang , Pengjie Zhang

Deep generative frameworks including GANs and normalizing flow models have proven successful at filling in missing values in partially observed data samples by effectively learning -- either explicitly or implicitly -- complex,…

Machine Learning · Computer Science 2021-04-06 Edgar A. Bernal