English
Related papers

Related papers: Isotropic covariance matrix functions on compact t…

200 papers

We show that homogeneous Einstein metrics on Euclidean spaces are Einstein solvmanifolds, using that they admit periodic, integrally minimal foliations by homogeneous hypersurfaces. For the geometric flow induced by the orbit-Einstein…

Differential Geometry · Mathematics 2022-06-29 Christoph Böhm , Ramiro A. Lafuente

In this paper we answer positively a question raised by Kapovich and Leeb in a paper titled "Finsler bordifications of symmetric and certain locally symmetric spaces". Specifically, we show that for a finite-dimensional vector space with a…

Geometric Topology · Mathematics 2024-05-09 Lizhen Ji , Anna-Sofie Schilling

We develop the scattering theory of general conformally compact metrics. For low frequencies, the domain of the scattering matrix is shown to be frequency dependent. In particular, generalized eigenfunctions exhibit L^2 decay in directions…

Spectral Theory · Mathematics 2007-05-23 David Borthwick

Matrix normal models have an associated 4-tensor for their covariance representation. The covariance array associated with a matrix normal model is naturally represented as a Kronecker-product structured covariance associated with the…

Computation · Statistics 2025-01-10 Quinn Simonis , Martin T. Wells

The modern definition of optical coherence highlights a frequency dependent function based on a matrix of spectra and cross-spectra. Due to general properties of matrices, such a function is invariant in changes of basis. In this article,…

Optics · Physics 2016-03-09 Bernard Lacaze

The Fourier coefficients of a smooth $K$-invariant function on a compact symmetric space $M=U/K$ are given by integration of the function against the spherical functions. For functions with support in a neighborhood of the origin, we…

Representation Theory · Mathematics 2010-02-23 Gestur Olafsson , Henrik Schlichtkrull

The wave functions of a quantum isotropic harmonic oscillator in N-space modified by barriers at the coordinate hyperplanes can be expressed in terms of certain generalized spherical harmonics. These are associated with a product-type…

Classical Analysis and ODEs · Mathematics 2009-11-07 Charles F. Dunkl

We prove ultradifferentiable Chevelley restriction theorems for a wide range of ultradifferentiable classes. As a special case we find that isotropic functions, i.e., functions defined on the vector space of real symmetric matrices…

Classical Analysis and ODEs · Mathematics 2019-12-20 Armin Rainer

We show injectivity of the geodesic X-ray transform on piecewise constant functions when the transform is weighted by a continuous matrix weight. The manifold is assumed to be compact and nontrapping of any dimension, and in dimension three…

Differential Geometry · Mathematics 2020-10-23 Joonas Ilmavirta , Jesse Railo

In this note, we generalize biharmonic equation for rotationally symmetric maps ([4], [16], [10]) to equivariant maps between model spaces and use it to give a complete classification of rotationally symmetric conformal biharmonic maps from…

Differential Geometry · Mathematics 2019-10-08 Ye-Lin Ou

We present a framework to describe completely general first-order perturbations of static, spatially compact, and locally rotationally symmetric class II spacetimes within the theory of general relativity. The perturbation variables are by…

General Relativity and Quantum Cosmology · Physics 2024-05-10 Paulo Luz , Sante Carloni

We derive explicit expressions for a family of radially symmetric, non-differentiable, Spartan covariance functions in $\mathbb{R}^2$ that involve the modified Bessel function of the second kind. In addition to the characteristic length and…

Statistics Theory · Mathematics 2015-02-03 Dionissios T. Hristopulos

This paper is devoted to the problem of classification, up to smooth isomorphisms or up to orbital equivalence, of smooth integrable vector fields on 2-dimensional surfaces, under some nondegeneracy conditions. The main continuous…

Dynamical Systems · Mathematics 2012-04-10 Nguyen Tien Zung , Nguyen Van Minh

We calculate the two-point correlation function and magnetic susceptibility in the anisotropic 2D Ising model on a lattice with one infinite and the other finite dimension, along which periodic boundary conditions are imposed. Using exact…

Exactly Solvable and Integrable Systems · Physics 2011-11-10 A. I. Bugrij , O. Lisovyy

A free massless scalar field is coupled to homogeneous and isotropic loop quantum cosmology. The coupled model is investigated in the vicinity of the classical singularity, where discreteness is essential and where the quantum model is…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Martin Bojowald , Franz Hinterleitner

We present an Eilenberg-Steenrod-like axiomatic framework for equivariant coarse homology and cohomology theories. We also discuss a general construction of such coarse theories from topological ones and the associated transgression maps. A…

Algebraic Topology · Mathematics 2022-07-27 Christopher Wulff

In this paper we consider invariant Matsumoto metrics which are induced by invariant Riemannian metrics and invariant vector fields on homogeneous spaces then we give the flag curvature formula of them. Also we study the special cases of…

Differential Geometry · Mathematics 2015-07-09 H. R. Salimi Moghaddam

We extend previous work concerning rest-frame partial-wave mixing in Hamiltonian effective field theory to both elongated and moving systems, where two particles are in a periodic elongated cube or have nonzero total momentum, respectively.…

High Energy Physics - Lattice · Physics 2021-05-26 Yan Li , Jia-jun Wu , Derek B. Leinweber , Anthony W. Thomas

In this study, we deal with the local structure of curves and surfaces immersed in a pseudo-isotropic space I_{p}^{3} that is a particular Cayley-Klein space. We provide the formulas of curvature, torsion and Frenet trihedron in order for…

Differential Geometry · Mathematics 2018-11-13 Muhittin Evren Aydin

Invariant functions under the transformations of a compact linear group $G$ acting in $\real^n$ can be expressed in terms of functions defined in the orbit space of $G$. We develop a method to determine the isotropy classes of the orbit…

High Energy Physics - Theory · Physics 2007-05-23 G. Sartori , G. Valente