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Inspired by recent interest in geometric deep learning, this work generalises the recently developed Slepian scale-discretised wavelets on the sphere to Riemannian manifolds. Through the sifting convolution, one may define translations and,…

Information Theory · Computer Science 2023-02-24 Patrick J. Roddy , Jason D. McEwen

We present a unified approach for constructing Slepian functions - also known as prolate spheroidal wave functions - on the sphere for arbitrary tensor ranks including scalar, vectorial, and rank 2 tensorial Slepian functions, using…

Classical Analysis and ODEs · Mathematics 2021-03-30 Volker Michel , Alain Plattner , Katrin Seibert

When modeling global satellite data to recover a planetary magnetic or gravitational potential field and evaluate it elsewhere, the method of choice remains their analysis in terms of spherical harmonics. When only regional data are…

Geophysics · Physics 2017-10-11 Alain Plattner , Frederik J. Simons

Many flexible parameterizations exist to represent data on the sphere. In addition to the venerable spherical harmonics, we have the Slepian basis, harmonic splines, wavelets and wavelet-like Slepian frames. In this paper we focus on the…

Data Analysis, Statistics and Probability · Physics 2013-06-14 Frederik J. Simons , Ignace Loris , Eugene Brevdo , Ingrid C. Daubechies

The recent development of spectral method has been praised for its high-order convergence in simulating complex physical problems. The combination of embedded boundary method and spectral method becomes a mainstream way to tackle…

Numerical Analysis · Mathematics 2018-03-08 Po-Yi Wu , Cheng-Hong Robert Kao , Tony Wen-Hann Sheu

We consider the vector functions in a domain homeomorphic to a spherical layer bounded by twice continuously differentiable surfaces. Additional restrictions are imposed on the domain, which allow to conduct proofs using simple methods. On…

Mathematical Physics · Physics 2020-10-23 V. V. Denisenko , S. A. Nesterov

A technique using vector Slepian harmonics and multipole fields is presented for a general treatment of the inverse problem of high numerical aperture focusing. A prescribed intensity distribution or electric field distribution in the focal…

Optics · Physics 2012-10-16 Kornél Jahn , Nándor Bokor

Structured light harnessing multiple degrees of freedom has become a powerful approach to use complex states of light in fundamental studies and applications. Here, we investigate the light field of an ultrafast laser beam with a…

We establish spectral rigidity for spherically symmetric manifolds with boundary and interior interfaces determined by discontinuities in the metric under certain conditions. Rather than a single metric, we allow two distinct metrics in…

Analysis of PDEs · Mathematics 2023-12-08 Joonas Ilmavirta , Maarten V. de Hoop , Vitaly Katsnelson

Slepian functions are orthogonal function systems that live on subdomains (for example, geographical regions on the Earth's surface, or bandlimited portions of the entire spectrum). They have been firmly established as a useful tool for the…

Numerical Analysis · Mathematics 2017-11-10 Volker Michel , Frederik J. Simons

We construct a pseudospectral method for the solution of time-dependent, non-linear partial differential equations on a three-dimensional spherical shell. The problem we address is the treatment of tensor fields on the sphere. As a test…

Computational Physics · Physics 2015-05-27 Bernd Bruegmann

Obtaining constraints from the largest scales of a galaxy survey is challenging due to the survey mask allowing only partial measurement of large angular modes. This scatters information from the harmonic-space 2-point function away from…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-16 Henry S. Grasshorn Gebhardt , Olivier Doré

We present in this paper a spectrally accurate numerical method for computing the spherical/vector spherical harmonic expansion of a function/vector field with given (elemental) nodal values on a spherical surface. Built upon suitable…

Numerical Analysis · Mathematics 2017-09-18 Bo Wang , Li-Lian Wang , Ziqing Xie

Spectral embedding uses eigenfunctions of the discrete Laplacian on a weighted graph to obtain coordinates for an embedding of an abstract data set into Euclidean space. We propose a new pre-processing step of first using the eigenfunctions…

Machine Learning · Statistics 2016-07-18 Alexander Cloninger , Stefan Steinerberger

Subspaces obtained by the orthogonal projection of locally supported square-integrable vector fields onto the Hardy spaces $H_+(\mathbb{S})$ and $H_-(\mathbb{S})$, respectively, play a role in various inverse potential field problems since…

Numerical Analysis · Mathematics 2023-07-06 Christian Gerhards , Xinpeng Huang

Spectral functions play a central role in the characterization of a wide range of physical systems, including strongly interacting quantum field theories and many-body systems. Their non-perturbative determination from Euclidean correlation…

High Energy Physics - Lattice · Physics 2026-04-16 Norikazu Yamada

In this paper, we characterize arbitrary polynomial vector fields on $S^n$. We establish a necessary and sufficient condition for a degree one vector field on the odd-dimensional sphere $S^{2n-1}$ to be Hamiltonian. Additionally, we…

Dynamical Systems · Mathematics 2024-12-04 Supriyo Jana , Soumen Sarkar

Segmentation, a useful/powerful technique in pattern recognition, is the process of identifying object outlines within images. There are a number of efficient algorithms for segmentation in Euclidean space that depend on the variational…

Computer Vision and Pattern Recognition · Computer Science 2019-11-12 Xiaohao Cai , Christopher G. R. Wallis , Jennifer Y. H. Chan , Jason D. McEwen

Identifying coherent spatiotemporal patterns generated by complex dynamical systems is a central problem in many science and engineering disciplines. Here, we combine ideas from the theory of operator-valued kernels with delay-embedding…

Data Analysis, Statistics and Probability · Physics 2018-05-24 Dimitrios Giannakis , Joanna Slawinska , Abbas Ourmazd , Zhizhen Zhao

In this tutorial paper, we consider the problem of electromagnetic scattering by a bounded two-dimensional dielectric object, and discuss certain interesting properties of the scattered field. Using the electric field integral equation,…

Optics · Physics 2015-07-08 Uday K. Khankhoje , Kushal Shah