Topologically left invariant means on semigroup algebras

Abstract

Let $M(S)$ be the Banach algebra of all bounded regular Borel measures on a locally compact Hausdorff semitopological semigroup $S$ with variation norm and convolution as multiplication. We obtain necessary and sufficient conditions for $M(S{)}^{\ast }$ to have a topologically left invariant mean.

arXiv comment7 pages