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Notes on the sin2\Theta\ theorem

Spectral Theory 2014-07-28 v1 Functional Analysis

Abstract

An analogue of the Davis-Kahan sin2\Theta\ theorem from [SIAM J. Numer. Anal. 7 (1970), 1--46] is proved under a general spectral separation condition. This extends the generic sin2\theta\ estimates recently shown by Albeverio and Motovilov in [Complex Anal. Oper. Theory 7 (2013), 1389--1416]. The result is applied to the subspace perturbation problem to obtain a bound on the arcsine of the norm of the difference of the spectral projections associated with isolated components of the spectrum of the unperturbed and perturbed operators, respectively.

Keywords

Cite

@article{arxiv.1310.2036,
  title  = {Notes on the sin2\Theta\ theorem},
  author = {Albrecht Seelmann},
  journal= {arXiv preprint arXiv:1310.2036},
  year   = {2014}
}

Comments

16 pages

R2 v1 2026-06-22T01:42:18.067Z