New extended Weyl type theorems

Authors

  • M. Berkani Department of Mathematics, Science faculty of Oujda, University Mohammed I, Team EQUITOMI, SFO, Laboratory MATSI, EST Author
  • H. Zariouh Department of Mathematics, Science faculty of Meknes, University Moulay Ismail Author

Keywords:

Property (ab), property (gab), property (aw), property (gaw)

Subjects:

47A53, 47A10, 47A11

Abstract

In this paper we introduce and study the new properties (ab),(gab), (aw) and (gaw) as a continuation of our previousarticle [4], where we introduced the two properties (b) and(gb).Among other, we prove that if T is a bounded linear operatoracting on a Banach space X, then T possesses property (gb) ifand only if T possesses property (gab) and \txind(T\lambdaI)=0 for all λınσa(T)σSBF+(T);where σSBF+(T) is the essential semi-B-Fredholmspectrum of T and σa(T) is the approximate spectrum ofT. We prove also that T possesses property (gaw) if and onlyif T possesses property (gab) and Ea(T)=Πa(T).

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Published

2010-04-15