Accurate algorithms for Bessel matrices
Jorge Delgado, Héctor Orera, Juan Manuel Peña
TL;DR
The paper establishes that collocation matrices of Bessel and reverse Bessel polynomials at positive nodes are strictly totally positive, enabling their bidiagonal factorization to be computed with high relative accuracy. This structure allows reliable, high-accuracy computation of eigenvalues, singular values, inverses, and linear system solutions via Koev's HRA algorithms. Numerical experiments demonstrate markedly improved accuracy over standard methods, particularly for small spectral values, and extend to both Bessel and reverse Bessel matrices across moderate sizes. The results provide a practical framework for accurate algebraic operations on these structured matrices and connect total positivity with Bessel function theory.
Abstract
In this paper, we prove that any collocation matrix of Bessel polynomials at positive points is strictly totally positive, that is, all its minors are positive. Moreover, an accurate method to construct the bidiagonal factorization of these matrices is obtained and used to compute with high relative accuracy the eigenvalues, singular values and inverses. Similar results for the collocation matrices for the reverse Bessel polynomials are also obtained. Numerical examples illustrating the theoretical results are included.
