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Structure Preserving Restarts of the Non-Symmetric Lanczos Algorithm via the Implicitly shifted LR algorithm

Computational Physics 2024-07-10 v1

Abstract

The implicitly shifted QR iteration is used as a restart procedure for the Arnoldi method for the calculation of a few dominant eigenvalues of a large matrix. We show that the underlying idea of implicit polynomial filtering can be utilized in much the same manner via the implicitly shifted LR iteration to create a restart procedure for the non-symmetric Lanczos algorithm for eigenvalue computations, which preserves the tri-diagonal structure of the reduced matrix.

Cite

@article{arxiv.2407.06561,
  title  = {Structure Preserving Restarts of the Non-Symmetric Lanczos Algorithm via the Implicitly shifted LR algorithm},
  author = {Prabal S. Negi and Cristobal Arratia},
  journal= {arXiv preprint arXiv:2407.06561},
  year   = {2024}
}
R2 v1 2026-06-28T17:33:52.254Z