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arXiv · 2309.07032

Relative residual bounds for eigenvalues in gaps of the essential spectrum

Albrecht Seelmann
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Abstract

The relative distance between eigenvalues of the compression of a not necessarily semibounded self-adjoint operator to a closed subspace and some of the eigenvalues of the original operator in a gap of the essential spectrum is considered. It is shown that this distance depends on the maximal angles between pairs of associated subspaces. This generalises results by Drma\v{c} in [Linear Algebra Appl. 244 (1996), 155--163] from matrices to not necessarily (semi)bounded operators.

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Albrecht Seelmann. 2023-09-13. Relative residual bounds for eigenvalues in gaps of the essential spectrum. https://doi.org/10.7153/oam-2024-18-13

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