English

Generalized Drazin-meromorphic invertible operators and generalized Kato-meromorphic decomposition

Spectral Theory 2019-04-10 v1 Functional Analysis

Abstract

A bounded linear operator TT on a Banach space XX is said to be generalized Drazin-meromorphic invertible if there exists a bounded linear operator SS acting on XX such that TS=STTS=ST, STS=SSTS=S, TSTT TST-T is meromorphic. We shall say that TT admits a generalized Kato-meromorphic decomposition if there exists a pair of TT-invariant closed subspaces (M,N)(M,N) such that X=MNX=M\oplus N, the reduction TMT_M is Kato and the reduction TNT_N is meromorphic. In this paper we shall investigate such kind of operators and corresponding spectra, the generalized Drazin-meromorphic spectrum and the generalized Kato-meromorphic spectrum, and prove that these spectra are empty if and only if the operator TT is polynomially meromorphic. Also we obtain that the generalized Kato-meromorphic spectrum differs from the Kato type spectrum on at most countably many points. Among others, bounded linear operators which can be expressed as a direct sum of a meromorphic operator and a bounded below (resp. surjective, upper (lower) semi-Fredholm, Fredholm, upper (lower) semi-Weyl, Weyl) operator are studied. In particular, we shall characterize the single-valued extension property at a point λ0C\lambda_0\in\mathbb{C} in the case that λ0T\lambda_0-T admits a generalized Kato-meromorphic decomposition. As a consequence we get several results on cluster points of some distinguished parts of the spectrum.

Keywords

Cite

@article{arxiv.1904.04757,
  title  = {Generalized Drazin-meromorphic invertible operators and generalized Kato-meromorphic decomposition},
  author = {Snežana Č. Živković-Zlatanović and Bhagwati P. Duggal},
  journal= {arXiv preprint arXiv:1904.04757},
  year   = {2019}
}
R2 v1 2026-06-23T08:34:25.302Z