Topologically Left Invariant Means on Semigroup Algebras

[摘要] 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 $M(S)^∗$ to have a topologically left invariant mean.

[学科分类] 数学（综合）

[关键词] Banach algebras;locally compact semigroup;topologically left invariant mean;fixed point.