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Related papers: On the Estimation of Anisotropic Covariance Functi…

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The covariance matrix function is characterized in this paper for a Gaussian or elliptically contoured vector random field that is stationary, isotropic, and mean square continuous on the compact two-point homogeneous space. Necessary and…

Probability · Mathematics 2019-05-20 Tianshi Lu , Chunsheng Ma

The spatial sign correlation (D\"urre, Vogel and Fried, 2015) is a highly robust and easy-to-compute, bivariate correlation estimator based on the spatial sign covariance matrix. Since the estimator is inefficient when the marginal scales…

Methodology · Statistics 2022-04-12 Alexander Dürre , Daniel Vogel

A general form of the covariance matrix function is derived in this paper for a vector random field that is isotropic and mean square continuous on a compact connected two-point homogeneous space and stationary on a temporal domain. A…

Probability · Mathematics 2018-11-15 Chunsheng Ma , Anatoliy Malyarenko

We study the two-point correlation function of density perturbations in a spherically symmetric void universe model which does not employ the Copernican principle. First we solve perturbation equations in the inhomogeneous universe model…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-25 Ryusuke Nishikawa , Chul-Moon Yoo , Ken-ichi Nakao

We propose nonparametric estimators for the second-order central moments of possibly anisotropic spherical random fields, within a functional data analysis context. We consider a measurement framework where each random field among an…

Statistics Theory · Mathematics 2022-06-28 Alessia Caponera , Julien Fageot , Matthieu Simeoni , Victor M. Panaretos

A new set of infinitesimal transformations generalizing scale invariance for strongly anisotropic critical systems is considered. It is shown that such a generalization is possible if the anisotropy exponent \theta =2/N, with N=1,2,3 ...…

Statistical Mechanics · Physics 2009-10-28 Malte Henkel

Recently E.Verlinde and H.Verlinde have suggested an effective two-dimensional theory describing the high-energy scattering in QCD. In this report we attempt to clarify some issues of this suggestion. We consider {\it anisotropic…

High Energy Physics - Theory · Physics 2007-05-23 I. Ya. Aref'eva , I. V. Volovich

We present sufficient condition for a family of positive definite kernels on a compact two-point homogeneous space to be strictly positive definite based on their representation as a series of spherical harmonics. The family analyzed is a…

Classical Analysis and ODEs · Mathematics 2022-05-17 Jean Carlo Guella , Janin Jäger

If one is willing to give up the cherished hypothesis of spatial isotropy, many interesting cosmological models can be developed beyond the simple anisotropically expanding scenarios. One interesting possibility is presented by shear-free…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-22 Thiago S. Pereira , Guillermo A. Mena Marugán , Saulo Carneiro

Rapid developments in satellite remote-sensing technology have enabled the collection of geospatial data on a global scale, hence increasing the need for covariance functions that can capture spatial dependence on spherical domains. We…

Methodology · Statistics 2022-08-17 Jian Cao , Jingjie Zhang , Zhuoer Sun , Matthias Katzfuss

In this paper we study the asymptotic theory for spectral analysis of stationary random fields, including linear and nonlinear fields. Asymptotic properties of Fourier coefficients and periodograms, including limiting distributions of…

Statistics Theory · Mathematics 2021-10-28 Wai Leong Ng , Chun Yip Yau

In this paper we investigate asymptotic isotropization. We derive the asymptotic dynamics of spatially inhomogeneous cosmological models with a perfect fluid matter source and a positive cosmological constant near the de Sitter equilibrium…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Woei Chet Lim , Henk van Elst , Claes Uggla , John Wainwright

A previous paper by the authors found explicit contour integral formulas for certain joint moments of the multi-species q-TAZRP (totally asymmetric zero range process), using algebraic methods. These contour integral formulas have a…

Probability · Mathematics 2024-03-14 Jeffrey Kuan , Zhengye Zhou

We consider a singularly perturbed second order elliptic system in the whole space. The coefficients of the systems fast oscillate and depend both of slow and fast variables. We obtain the homogenized operator and in the uniform norm sense…

Mathematical Physics · Physics 2007-05-23 Denis Borisov

We consider point distributions in compact connected two-point homogeneous spaces (Riemannian symmetric spaces of rank one). All such spaces are known, they are the spheres in the Euclidean spaces, the real, complex and quaternionic…

Metric Geometry · Mathematics 2018-02-02 M. M. Skriganov

The standard estimator for the two-point function of a homogeneous and isotropic random field is a special case of a larger class of least squares estimators that interpolate the function values. Using a different interpolation scheme,…

Instrumentation and Methods for Astrophysics · Physics 2018-08-17 Nicolas Tessore

We consider singularly perturbed second order elliptic system in the whole space with fast oscillating coefficients. We construct the complete asymptotic expansions for the eigenvalues converging to the isolated ones of the homogenized…

Spectral Theory · Mathematics 2007-05-30 D. Borisov

We first review the $L^2$ bilinear generalizations of the $L^4$ estimate of Strichartz for solutions of the homogeneous 3D wave equation, and give a short proof based solely on an estimate for the volume of intersection of two thickened…

Analysis of PDEs · Mathematics 2008-04-29 Sigmund Selberg

This paper is concerned with the asymptotic optimality of spectral coarse spaces for two-level iterative methods. Spectral coarse spaces, namely coarse spaces obtained as the span of the slowest modes of the used one-level smoother, are…

Numerical Analysis · Mathematics 2021-03-18 Gabriele Ciaramella , Tommaso Vanzan

We consider effects of anisotropy on solitons of various types in two-dimensional nonlinear lattices, using the discrete nonlinear Schr{\"{o}}dinger equation as a paradigm model. For fundamental solitons, we develop a variational…

Pattern Formation and Solitons · Physics 2010-12-10 P. G. Kevrekidis , D. J. Frantzeskakis , R. Carretero-Gonzalez , B. A. Malomed , A. R. Bishop
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