English

On a minimax principle in spectral gaps

Spectral Theory 2022-03-04 v3 Mathematical Physics Functional Analysis math.MP

Abstract

The minimax principle for eigenvalues in gaps of the essential spectrum in the form presented by Griesemer, Lewis, and Siedentop in [Doc. Math. 4 (1999), 275--283] is adapted to cover certain abstract perturbative settings with bounded or unbounded perturbations, in particular ones that are off-diagonal with respect to the spectral gap under consideration. This in part builds upon and extends the considerations in the author's appendix to [J. Spectr. Theory 10 (2020), 843--885]. Several monotonicity and continuity properties of eigenvalues in gaps of the essential spectrum are deduced, and the Stokes operator is revisited as an example.

Keywords

Cite

@article{arxiv.2008.02489,
  title  = {On a minimax principle in spectral gaps},
  author = {Albrecht Seelmann},
  journal= {arXiv preprint arXiv:2008.02489},
  year   = {2022}
}

Comments

31 pages; modified introduction, added references and appendix, some editorial changes and fixed typos

R2 v1 2026-06-23T17:40:31.060Z