Drazin spectra of Banach space operators and Banach algebra elements

摘要

Given a Banach algebra A and a ∈ A, several relations among the Drazin spectrum of a and the Drazin spectra of the multiplication operators L_a and R_a will be stated. The Banach space operator case will be also examined. Furthermore, a characterization of the Drazin spectrum will be considered.