One-sided essentially Drazin-invertible multivalued linear operators
摘要
The purpose of this paper is to initiate the study of the classes of essentially left and essentially right Drazin-invertible multivalued linear operators on Banach spaces. It is shown, among other results, that these multivalued operators can be completely characterized in terms of a direct sum decomposition consisting of a left (right) Fredholm multivalued operator and a bounded nilpotent operator. As a consequence of these decompositions, many other characterizations of these multivalued operators are obtained. More precisely, we provide another type of decomposition for essentially left and essentially right Drazin-invertible multivalued operators via the new notion of normal decomposability, and we also characterize them using restrictions and projections. We then show the connection between these multivalued operators and B-Fredholm multivalued operators. The results obtained in this study generalize and enhance certain characterizations previously established in [