On the ranks of Elements of Semiprime Banach Algebras
Από το τεύχος 49 του περιοδικού Δελτίο της Ελληνικής Μαθηματικής Εταιρίας
We give spectral characterizations of rank one elements and the socle of a semiprime Banach algebra. The main tool used is the concept of a ? single ? element. If A is any algebra an element s of A is called ? single ? element, if whenever αsb = 0 for some a,b ε A, at least one of as, sb is zero