English

Sobolev-Orthogonal Systems with Tridiagonal Skew-Hermitian Differentiation Matrices

Classical Analysis and ODEs 2022-06-16 v1 Numerical Analysis Numerical Analysis

Abstract

We introduce and develop a theory of orthogonality with respect to Sobolev inner products on the real line for sequences of functions with a tridiagonal, skew-Hermitian differentiation matrix. While a theory of such L2-orthogonal systems is well established, Sobolev orthogonality requires new concepts and their analysis. We characterise such systems completely as appropriately weighed Fourier transforms of orthogonal polynomials and present a number of illustrative examples, inclusive of a Sobolev-orthogonal system whose leading N coefficients can be computed in O(NlogN)\mathcal{O}(N \log N) operations.

Keywords

Cite

@article{arxiv.2206.07560,
  title  = {Sobolev-Orthogonal Systems with Tridiagonal Skew-Hermitian Differentiation Matrices},
  author = {Arieh Iserles and Marcus Webb},
  journal= {arXiv preprint arXiv:2206.07560},
  year   = {2022}
}
R2 v1 2026-06-24T11:52:30.997Z