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Random fields are useful mathematical tools for representing natural phenomena with complex dependence structures in space and/or time. In particular, the Gaussian random field is commonly used due to its attractive properties and…

Gaussian Markov random fields (GMRFs) are frequently used as computationally efficient models in spatial statistics. Unfortunately, it has traditionally been difficult to link GMRFs with the more traditional Gaussian random field models as…

Statistics Theory · Mathematics 2011-11-01 Daniel Simpson , Finn Lindgren , Håvard Rue

We study spherically symmetric spacetimes for matter distributions with isotropic pressures. We generate new exact solutions to the Einstein field equations which also contains isotropic pressures. We develop an algorithm that produces a…

General Relativity and Quantum Cosmology · Physics 2014-12-23 S. Ngubelanga , S. D. Maharaj

Random fields play a central role in the analysis of spatially correlated data and, as a result, have a significant impact on a broad array of scientific applications. This paper studies the cepstral random field model, providing recursive…

Statistics Theory · Mathematics 2014-01-17 Tucker S. McElroy , Scott H. Holan

Gaussian random fields have been one of the most popular tools for analyzing spatial data. However, many geophysical and environmental processes often display non-Gaussian characteristics. In this paper, we propose a new class of spatial…

Applications · Statistics 2017-10-03 Minjie Fan , Debashis Paul , Thomas C. M. Lee , Tomoko Matsuo

In the first part of the series papers, we set out to answer the following question: given specific restrictions on a set of samplers, what kind of signal can be uniquely represented by the corresponding samples attained, as the foundation…

Information Theory · Computer Science 2021-08-25 Hanshen Xiao , Yaowen Zhang , Guoqiang Xiao

In this paper, we are concerned with sample path properties of isotropic spherical Gaussian fields on $\S^2$. In particular, we establish the property of strong local nondeterminism of an isotropic spherical Gaussian field based on the…

Probability · Mathematics 2021-12-01 Xiaohong Lan , Domenico Marinucci , Yimin Xiao

Cosmological simulations play a crucial role in elucidating the effect of physical parameters on the statistics of fields and on constraining parameters given information on density fields. We leverage diffusion generative models to address…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-13 Nayantara Mudur , Carolina Cuesta-Lazaro , Douglas P. Finkbeiner

A flexible model for non-stationary Gaussian random fields on hypersurfaces is introduced.The class of random fields on curves and surfaces is characterized by an amplitude spectral density of a second order elliptic differential…

Numerical Analysis · Mathematics 2024-12-02 Erik Jansson , Annika Lang , Mike Pereira

Known algorithms for manipulating octagons do not preserve their sparsity, leading typically to quadratic or cubic time and space complexities even if no relation among variables is known when they are all bounded. In this paper, we present…

Programming Languages · Computer Science 2016-12-02 Jacques-Henri Jourdan

Instance sparsification is well-known in the world of exact computation since it is very closely linked to the Exponential Time Hypothesis. In this paper, we extend the concept of sparsification in order to capture subexponential time…

Computational Complexity · Computer Science 2014-02-17 Edouard Bonnet , Vangelis Th. Paschos

Motivated by the need to better understand the properties of sparse cutting-planes used in mixed integer programming solvers, the paper [2] studied the idealized problem of how well a polytope is approximated by the use of sparse valid…

Optimization and Control · Mathematics 2014-12-12 Santanu S. Dey , Andres Iroume , Marco Molinaro

We show that sparse spherical harmonic expansions can be efficiently recovered from a small number of randomly chosen samples on the sphere. To establish the main result, we verify the restricted isometry property of an associated…

Numerical Analysis · Mathematics 2011-02-22 Holger Rauhut , Rachel Ward

Several extensions of General Relativity and high energy physics include scalar fields as extra degrees of freedom. In the search for predictions in the non-linear regime of cosmological evolution, the community makes use of numerical…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-04 Claudio Llinares , David Mota

Geometric reconstruction of opaque surfaces from images is a longstanding challenge in computer vision, with renewed interest from volumetric view synthesis algorithms using radiance fields. We leverage the geometry field proposed in recent…

Graphics · Computer Science 2025-03-31 Kaiwen Jiang , Venkataram Sivaram , Cheng Peng , Ravi Ramamoorthi

In this paper we will consider the problem of the numerical simulation of non-Gaussian, scalar random fields with a prescribed correlation structure provided either by a theoretical model or computed on a set of observational data.…

Astrophysics · Physics 2009-11-06 Roberto Vio , Paola Andreani , Willem Wamsteker

The next generation of galaxy surveys, aiming to observe millions of galaxies, are expensive both in time and cost. This raises questions regarding the optimal investment of this time and money for future surveys. In a previous work, it was…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-23 P. Paykari , S. Pires , J. -L. Starck , A. H. Jaffe

The problem of how to find a sparse representation of a signal is an important one in applied and computational harmonic analysis. It is closely related to the problem of how to reconstruct a sparse vector from its projection in a much…

Functional Analysis · Mathematics 2018-04-13 Enrico Au-Yeung

We develop a technique for the reconstruction of the potential for a scalar field or a tachyon field, reproducing a given cosmological evolution in a closed and open isotropic cosmological models. Such potentials are explicitly written down…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Alexander Y. Kamenshchik , Serena Manti

Random feature methods have been successful in various machine learning tasks, are easy to compute, and come with theoretical accuracy bounds. They serve as an alternative approach to standard neural networks since they can represent…

Machine Learning · Statistics 2026-01-21 Abolfazl Hashemi , Hayden Schaeffer , Robert Shi , Ufuk Topcu , Giang Tran , Rachel Ward
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