TITLE: Must there always be a normal element with non-discrete spectrum in an infinite-dimensional C*-algebra?
QUESTION [7 upvotes]: Suppose that $A$ is an infinite-dimensional $C^*$-algebra. Is it true that there must be a normal element with non-discrete spectrum? If that is not true must there at least be a normal element with infinite spectrum?
Edit: To clarify, by discrete spectrum I mean that the spectrum consists only of isolated points. Since the spectrum is closed this is the same as saying that it has no accumulation points. 
I have also found, via MathOverflow, the following article which claims that there if $A$ is semi-simple there exists a self-adjoint element in $A$ with infinite spectrum.

REPLY [7 votes]: Yes it is true.  As mentioned in the article you linked to in the Remark on page 4, every infinite dimensional C*-algebra contains a self-adjoint element with infinite spectrum.  (In context it helps to know that every C*-algebra is semi-simple.)  A reference is given to Ogasawara's "Finite dimensionality of certain Banach algebras," which doesn't appear to be readily available online.  (I do not have a more easily accessible reference or proof off hand.)  Note that the only compact discrete subsets of $\mathbb C$ are the finite subsets, so your two questions are the same.