English

Factorizations and fast diagonalization for the heat equation

Numerical Analysis 2025-05-09 v2 Numerical Analysis

Abstract

This work investigates diagonalization-based methods for efficiently solving linear evolution problems, with a particular focus on the heat equation. The plain diagonalization of the differential operator, though effective for elliptic problems where fast diagonalization can be used, exhibits instability when applied to the heat equation. To address this difficulty, we examine three alternative approaches, based on LU factorization, a suitable arrowhead factorization, and a low-rank modification. These methods introduce more robust factorizations of the time derivative, ensuring both computational efficiency and stability.

Keywords

Cite

@article{arxiv.2403.07875,
  title  = {Factorizations and fast diagonalization for the heat equation},
  author = {Andrea Bressan and Alen Kushova and Gabriele Loli and Monica Montardini and Giancarlo Sangalli and Mattia Tani},
  journal= {arXiv preprint arXiv:2403.07875},
  year   = {2025}
}

Comments

arXiv admin note: substantial text overlap with arXiv:1909.07309, arXiv:2311.18461

R2 v1 2026-06-28T15:17:39.042Z