Browder and semi-Browder operators and perturbation function

• Autores: Fatma Fakhfakh, Maher Mnif
• Localización: Extracta mathematicae, ISSN-e 0213-8743, Vol. 24, Nº 3, 2009, págs. 219-241
• Idioma: inglés
• Enlaces
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• Resumen

  • This paper is devoted to the investigation of the stability of closed densely de¯ned semi-Browder and Browder operators on Banach spaces. Our approach consists to introduce the concepts of a perturbation function and a coperturbation function in order to deduce the stability under strictly singular and cosingular operator perturbations. Further, our results are used to show the invariance of Browder's spectrum