2010/02/17 by Vern I. Paulsen, Paulsen, Vern I.
Mathematics · #22D05 #FOS: Mathematics #Functional Analysis (math.FA) #Operator Algebras (math.OA) #math.FA #math.OA #msc:22D05
paper · pdf · doi:10.48550/arxiv.1002.3157
arxiv created 2011/02/02 · arxiv updated 2011/02/03
We prove that if an infinite, discrete semigroup has the property that every right syndetic set is left syndetic, then the semigroup has a left invariant mean. We prove that the weak*-closed convex hull of the two-sided translates of every bounded function on an infinite discrete semigroup contains a constant function. Our proofs use the algebraic properties of the Stone-Cech compactification.