ESSENTIAL APPROXIMATE POINT AND ESSENTIAL DEFECT SPECTRUM OF A SEQUENCE OF LINEAR OPERATORS IN BANACH SPACES

TOUFIK, HERAIZ2020-11-182020-11-182019http://dspace.univ-msila.dz:8080//xmlui/handle/123456789/20667This paper is devoted to an investigation of the relationship between the essential approximate point spectrum (respectively, the essential defect spectrum) of a sequence of closed linear operators (Tn)n2N on a Banach space X, and the essential approximate point spectrum (respectively, the essential defect spectrum) of a linear operator T on X, where (Tn)n2N converges to T, in the case of convergence in generalized sense as well as in the case of the convergence compactlyESSENTIAL APPROXIMATE POINT AND ESSENTIAL DEFECT SPECTRUM OF A SEQUENCE OF LINEAR OPERATORS IN BANACH SPACESArticle