English

Spectra originated from semi-B-Fredholm theory and commuting perturbations

Functional Analysis 2014-03-07 v1

Abstract

Burgos, Kaidi, Mbekhta and Oudghiri provided an affirmative answer to a question of Kaashoek and Lay and proved that an operator FF is power finite rank if and only if σdsc(T+F)=σdsc(T)\sigma_{dsc}(T+F) =\sigma_{dsc}(T) for every operator TT commuting with FF. Later, several authors extended this result to the essential descent spectrum, the left Drazin spectrum and the left essentially Drazin spectrum. In this paper, using the theory of operator with eventual topological uniform descent and the technique used in Burgos, Kaidi, Mbekhta, and Oudghiri, we generalize this result to various spectra originated from seni-B-Fredholm theory. As immediate consequences, we give affirmative answers to several questions posed by Berkani, Amouch and Zariouh. Besides, we provide a general framework which allows us to derive in a unify way commuting perturbational results of Weyl-Browder type theorems and properties (generalized or not). These commuting perturbational results, in particular, improve many recent results of Berkani and Amouch, Berkani and Zariouh, and Rashid by removing certain extra assumptions.

Keywords

Cite

@article{arxiv.1203.2442,
  title  = {Spectra originated from semi-B-Fredholm theory and commuting perturbations},
  author = {Qingping Zeng and Qiaofen Jiang and Huaijie Zhong},
  journal= {arXiv preprint arXiv:1203.2442},
  year   = {2014}
}

Comments

18 pages