MONATSHEFTE FUR MATHEMATIK, cilt.165, ss.413-432, 2012 (SCI-Expanded)
Let S be a suitable subsemigroup of a locally compact abelian group. We consider the class of Banach algebras A for which there exists a continuous homomorphism omega : L (1) (S) -> A with dense range. We study the behavior of the radical in such algebras. As an application, we present some results concerning the structure of weakly compact homomorphisms of semigroup algebras.