topologically irreducible representations are algebrically irreducible for -algebras
Theorem - Every topologically irreducible representation (http://planetmath.org/BanachAlgebraRepresentation) of a -algebra
(http://planetmath.org/CAlgebra) is algebraically irreducible.
It follows easily from the definition that algebraically irreducible of any Banach *-algebra are always topologically irreducible. The above theorem says that for -algebras the converse is also true.