Numerical methods for nonlocal and fractional models

M D'Elia, Q Du, C Glusa, M Gunzburger, X Tian… - Acta Numerica, 2020 - cambridge.org
Partial differential equations (PDEs) are used with huge success to model phenomena
across all scientific and engineering disciplines. However, across an equally wide swath …

Fast algorithms using orthogonal polynomials

S Olver, RM Slevinsky, A Townsend - Acta Numerica, 2020 - cambridge.org
We review recent advances in algorithms for quadrature, transforms, differential equations
and singular integral equations using orthogonal polynomials. Quadrature based on …

Tensor calculus in spherical coordinates using Jacobi polynomials. Part-I: mathematical analysis and derivations

GM Vasil, D Lecoanet, KJ Burns, JS Oishi… - Journal of Computational …, 2019 - Elsevier
This paper presents a method for accurate and efficient computations on scalar, vector and
tensor fields in three-dimensional spherical polar coordinates. The method uses spin …

Polynomial and rational measure modifications of orthogonal polynomials via infinite-dimensional banded matrix factorizations

TS Gutleb, S Olver, RM Slevinsky - Foundations of Computational …, 2024 - Springer
We describe fast algorithms for approximating the connection coefficients between a family
of orthogonal polynomials and another family with a polynomially or rationally modified …

cunuSHT: GPU accelerated spherical harmonic transforms on arbitrary pixelizations

S Belkner, AJ Duivenvoorden, J Carron… - RAS Techniques …, 2024 - academic.oup.com
We present cunuSHT, a general-purpose Python package that wraps a highly efficient
CUDA implementation of the non-uniform spin-0 spherical harmonic transform. The method …

A sparse spectral method on triangles

S Olver, A Townsend, G Vasil - SIAM Journal on Scientific Computing, 2019 - SIAM
In this paper, we demonstrate that many of the computational tools for univariate orthogonal
polynomials have analogues for a family of bivariate orthogonal polynomials on the triangle …

Computing equilibrium measures with power law kernels

T Gutleb, J Carrillo, S Olver - Mathematics of Computation, 2022 - ams.org
We introduce a method to numerically compute equilibrium measures for problems with
attractive-repulsive power law kernels of the form $ K (xy)=\frac {| xy|^\alpha}{\alpha}-\frac …

Orthogonal polynomials in and on a quadratic surface of revolution

S Olver, Y Xu - Mathematics of Computation, 2020 - ams.org
We present explicit constructions of orthogonal polynomials inside quadratic bodies of
revolution, including cones, hyperboloids, and paraboloids. We also construct orthogonal …

Explicit fractional Laplacians and Riesz potentials of classical functions

TS Gutleb, I Papadopoulos - arXiv preprint arXiv:2311.10896, 2023 - arxiv.org
We prove and collect numerous explicit and computable results for the fractional Laplacian
$(-\Delta)^ sf (x) $ with $ s> 0$ as well as its whole space inverse, the Riesz potential …

Sparse spectral methods for partial differential equations on spherical caps

B Snowball, S Olver - Transactions of Mathematics and Its …, 2021 - academic.oup.com
In recent years, sparse spectral methods for solving partial differential equations have been
derived using hierarchies of classical orthogonal polynomials (OPs) on intervals, disks, disk …