Lower characteristic, demicompact linear operators, and essential spectra
Sami Baraket, Anis Ben Ghorbal, Aref Jeribi · Filomat · 2024
In this paper, we present some results on the ?lower? characteristic involving demicompact operators. They are used to establish a fine description of the B-Weyl spectrum, and to investigate some perturbation results. Finally, some results concerning the Schechter and Jeribi essential spectra are given.