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Standard geostatistical models assume second order stationarity of the underlying Random Function. In some instances, there is little reason to expect the spatial dependence structure to be stationary over the whole region of interest. In…

Methodology · Statistics 2014-12-04 Francky Fouedjio , Nicolas Desassis , Jacques Rivoirard

We consider a stationary spatio-temporal random process and assume that we have a sample. By defining a sequence of discrete Fourier transforms at canonical frequencies at each location, and using these complex valued random varables as…

Statistics Theory · Mathematics 2015-12-31 T. Subba Rao , Gy. Terdik

Functional data, with basic observational units being functions (e.g., curves, surfaces) varying over a continuum, are frequently encountered in various applications. While many statistical tools have been developed for functional data…

Methodology · Statistics 2016-06-10 Jingjing Yang , Hongxiao Zhu , Taeryon Choi , Dennis D. Cox

The Mat\'ern covariance function is a popular choice for prediction in spatial statistics and uncertainty quantification literature. A key benefit of the Mat\'ern class is that it is possible to get precise control over the degree of…

Statistics Theory · Mathematics 2021-11-03 Pulong Ma , Anindya Bhadra

In modeling spatial processes, a second-order stationarity assumption is often made. However, for spatial data observed on a vast domain, the covariance function often varies over space, leading to a heterogeneous spatial dependence…

Methodology · Statistics 2021-02-09 Ghulam A. Qadir , Ying Sun , Sebastian Kurtek

Series expansions of isotropic Gaussian random fields on $\mathbb{S}^2$ with independent Gaussian coefficients and localized basis functions are constructed. Such representations with multilevel localised structure provide an alternative to…

Probability · Mathematics 2022-06-27 Markus Bachmayr , Ana Djurdjevac

The migration of planets within their nascent protoplanetary disks is a fundamental process that shapes the final architecture of planetary systems. However, studying this phenomenon through direct hydrodynamical simulations is…

Earth and Planetary Astrophysics · Physics 2026-01-14 Ximena S. Ramos , Pablo Benitez-Llambay

We extend generalized functional linear models under independence to a situation in which a functional covariate is related to a scalar response variable that exhibits spatial dependence-a complex yet prevalent phenomenon. For estimation,…

Methodology · Statistics 2026-05-22 Sooran Kim , Mark S. Kaiser , Xiongtao Dai

Deformations of spacelike hypersurfaces in space-time play an important role in discussions of general covariance and slicing independence in gravitational theories. In a canonical formulation, they provide the geometrical meaning of gauge…

General Relativity and Quantum Cosmology · Physics 2025-07-22 Martin Bojowald , Erick I. Duque , Aiden Shah

In multivariate time series, the estimation of the covariance matrix of the observation innovations plays an important role in forecasting as it enables the computation of the standardized forecast error vectors as well as it enables the…

Methodology · Statistics 2008-02-04 K. Triantafyllopoulos

Motivated by a large ground-level ozone dataset, we propose a new computationally efficient additive approximate Gaussian process. The proposed method incorporates a computational-complexity-reduction method and a separable covariance…

Methodology · Statistics 2019-06-10 Pulong Ma , Bledar A. Konomi , Emily L. Kang

Quantifying uncertainty in future climate projections is hindered by the prohibitive computational cost of running physical climate models, which severely limits the availability of training data. We propose a data-efficient framework for…

Methodology · Statistics 2026-02-27 Johannes Brachem , Paul F. V. Wiemann , Matthias Katzfuss

We present a covariant formalism for general multi-field system which enables us to obtain higher order action of cosmological perturbations easily and systematically. The effects of the field space geometry, described by the Riemann…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-17 Jinn-Ouk Gong , Takahiro Tanaka

Spatial functional data arise in many settings, such as particulate matter curves observed at monitoring stations and age population curves at each areal unit. Most existing functional regression models have limited applicability because…

Methodology · Statistics 2025-04-25 Heesang Lee , Dagun Oh , Sunhwa Choi , Jaewoo Park

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

A flexible model is developed for multivariate generalized spherical distributions, i.e. ones with level sets that are star shaped. To work in dimension above 2 requires tools from computational geometry and multivariate numerical…

Computation · Statistics 2015-10-26 John P Nolan

Atmospheric inverse modelling is a method for reconstructing historical fluxes of green-house gas between land and atmosphere, using observed atmospheric concentrations and an atmospheric tracer transport model. The small number of observed…

Applications · Statistics 2019-07-08 Unn Dahlen , Johan Linström , Marko Scholze

Physicists routinely need probabilistic models for a number of tasks such as parameter inference or the generation of new realizations of a field. Establishing such models for highly non-Gaussian fields is a challenge, especially when the…

Data Analysis, Statistics and Probability · Physics 2024-10-07 Sihao Cheng , Rudy Morel , Erwan Allys , Brice Ménard , Stéphane Mallat

Microfading Spectrometry (MFS) is a method for assessing light sensitivity color (spectral) variations of cultural heritage objects. Each measured point on the surface gives rise to a time-series of stochastic observations that represents…

We study covariant models for vacuum spherical gravity within a canonical setting. Starting from a general ansatz, we derive the most general family of Hamiltonian constraints that are quadratic in first-order and linear in second-order…

General Relativity and Quantum Cosmology · Physics 2024-10-04 Asier Alonso-Bardaji , David Brizuela