Abstract
Let A be a Banach -algebra with an identity, continuous involution, center Z and set of self-adjoint elements . Let h 2 . The set of v 2 such that (h +iv) n is normal for no positive integer n is dense in if and only if h62 Z. The case where A has no identity is also treated.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have