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Related papers: Non-linear Reconstruction of the Large Scale Struc…

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Spatial fields in the Earth and environmental sciences are often available at multiple scales or resolutions. While coarse-scale data (e.g., from global circulation models) are often abundant, they lack the local detail provided by…

Methodology · Statistics 2026-04-01 Alejandro Calle-Saldarriaga , Paul F. V. Wiemann , Matthias Katzfuss

We develop a new approach to study the nonlinear evolution in the large-scale structure of the Universe both in real space and in redshift space, extending the standard perturbation theory of gravitational instability. Infinite series of…

Astrophysics · Physics 2008-11-26 Takahiko Matsubara

Percus showed that approximate theories for the structure of nonuniform hard sphere fluids can be generated by linear truncations of functional expansions of the nonuniform density rho (r) about that of an appropriately chosen uniform…

Statistical Mechanics · Physics 2007-05-23 Yng-Gwei Chen , John D. Weeks

On the smallest scales, three-dimensional large-scale structure surveys contain a wealth of cosmological information which cannot be trivially extracted due to the non-linear dynamical evolution of the density field. Lagrangian perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-05 Florent Leclercq , Jens Jasche , Héctor Gil-Marín , Benjamin Wandelt

In this article, we introduce parallel-in-time methods for state and parameter estimation in general nonlinear non-Gaussian state-space models using the statistical linear regression and the iterated statistical posterior linearization…

Computation · Statistics 2023-04-06 Fatemeh Yaghoobi , Adrien Corenflos , Sakira Hassan , Simo Särkkä

This paper deals with the use of Reconfigurable Intelligent Surfaces (RISs) for radar surveillance in Non-Line Of Sight (N-LOS) scenarios. First of all, the geometry of the scene and the new system concept is described with emphasis on the…

Signal Processing · Electrical Eng. & Systems 2022-12-09 Augusto Aubry , Antonio De Maio , Massimo Rosamilia

Kernel ridge regression (KRR) is widely used for nonparametric regression over reproducing kernel Hilbert spaces. It offers powerful modeling capabilities at the cost of significant computational costs, which typically require $O(n^3)$…

Methodology · Statistics 2024-03-18 Xiaowu Dai , Huiying Zhong

In this work we present a nonparametric approach, which works on minimal assumptions, to reconstruct the cosmic expansion of the Universe. We propose to combine a locally weighted scatterplot smoothing method and a simulation-extrapolation…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-20 Ariadna Montiel , Ruth Lazkoz , Irene Sendra , Celia Escamilla-Rivera , Vincenzo Salzano

In this work we investigate the nonlinear and nonlocal relation between cosmological density and peculiar velocity fields. Our goal is to provide an algorithm for the recon- struction of the nonlinear velocity field from the fully nonlinear…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Francisco-Shu Kitaura , Raul E. Angulo , Yehuda Hoffman , Stefan Gottl"ober

The application of Gaussian processes (GPs) to large data sets is limited due to heavy memory and computational requirements. A variety of methods has been proposed to enable scalability, one of which is to exploit structure in the kernel…

Machine Learning · Computer Science 2019-12-30 Jan Graßhoff , Alexandra Jankowski , Philipp Rostalski

Non-local self-similarity in natural images has been well studied as an effective prior in image restoration. However, for single image super-resolution (SISR), most existing deep non-local methods (e.g., non-local neural networks) only…

Computer Vision and Pattern Recognition · Computer Science 2020-10-21 Shangchen Zhou , Jiawei Zhang , Wangmeng Zuo , Chen Change Loy

Motivated by the limitations encountered with the commonly used direct reconstruction techniques of producing mass maps, we have developed a multi-resolution maximum-likelihood reconstruction method for producing two dimensional mass maps…

Astrophysics · Physics 2009-11-13 H. Khiabanian , I. P. Dell'Antonio

Many scientific and engineering applications require fitting regression models that are nonlinear in the parameters. Advances in computer hardware and software in recent decades have made it easier to fit such models. Relative to fitting…

Methodology · Statistics 2024-03-20 Peng Liu , William Q. Meeker

We present a method to reconstruct the initial linear-regime matter density field from the late-time non-linearly evolved density field in which we channel the output of standard first-order reconstruction to a convolutional neural network…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-23 Christopher J. Shallue , Daniel J. Eisenstein

We discuss the constraints imposed on the nonlinear evolution of the Large Scale Structure (LSS) of the universe by galilean invariance, the symmetry relevant on subhorizon scales. Using Ward identities associated to the invariance, we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Marco Peloso , Massimo Pietroni

Automated sensing instruments on satellites and aircraft have enabled the collection of massive amounts of high-resolution observations of spatial fields over large spatial regions. If these datasets can be efficiently exploited, they can…

Methodology · Statistics 2015-12-08 Matthias Katzfuss

Computational reconstruction plays a vital role in computer vision and computational photography. Most of the conventional optimization and deep learning techniques explore local information for reconstruction. Recently, nonlocal low-rank…

Image and Video Processing · Electrical Eng. & Systems 2023-01-10 Daoyu Li , Hanwen Xu , Miao Cao , Xin Yuan , David J. Brady , Liheng Bian

We use cosmological simulations to explore the large-scale effects of reionization. Since reionization is a process that involves a large dynamic range - from galaxies to rare bright quasars - we need to be able to cover a significant…

Astrophysics · Physics 2008-11-26 Katharina Kohler , Nickolay Y. Gnedin , Andrew J. S. Hamilton

The acquisition of Magnetic Resonance Imaging (MRI) is inherently slow. Inspired by recent advances in deep learning, we propose a framework for reconstructing MR images from undersampled data using a deep cascade of convolutional neural…

Computer Vision and Pattern Recognition · Computer Science 2017-03-03 Jo Schlemper , Jose Caballero , Joseph V. Hajnal , Anthony Price , Daniel Rueckert

Combining fast MR acquisition sequences and high resolution imaging is a major issue in dynamic imaging. Reducing the acquisition time can be achieved by using non-Cartesian and sparse acquisitions. The reconstruction of MR images from…

Computer Vision and Pattern Recognition · Computer Science 2009-08-25 R. Boubertakh , J. -F. Giovannelli , A. Herment , A. De Cesare
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