Definition:Normal Element of *-Algebra

Definition

Let $\struct {A, \ast}$ be a $\ast$-algebra.

Let $a \in A$.

We say that $a$ is normal if and only if:

$a^\ast a = a a^\ast$

Sources

• 1990: Gerard J. Murphy: C*-Algebras and Operator Theory ... (previous) ... (next): $2.1$: $C^\ast$-Algebras