International Journal of Mathematics and Mathematical Sciences
Volume 16 (1993), Issue 4, Pages 819-822
Comparisons between different spectra of an element in a Banach algebra
Dipartimento di Matematica dell'Università di Genova, Via L.B. Alberti 4, Genova 16132, Italy
Received 26 June 1990
Copyright © 1993 Laura Burlando. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
In this paper we study the relationships among the spectra of the cosets of an
element of a Banach algebra in some quotient algebras. We also characterize the spectrum of any
(where is an ideal of a Banach algebra with identity and moreover has an identity) in the
whole algebra in terms of the spectrum of in .