Geometric and topological properties of certain $w^{\ast}$ compact convex subsets of double duals of banach spaces, which arise from the study of invariant means
Edmond E. Granirer · Illinois Journal of Mathematics · 1986
bounded (assumed embeded in X**) S a countable set of operators s,: X-X,A {yw*clK; s,*y=0 for all n} and if some nonvoid w* G,-section A o of A can be pushed outside the w*-sequential closure of K (w*seq cl K) then A o is necessarily "big".Specifically we have: THEOREM 1.4.Let X be a Banach space, S a sequence of operators s" X ---> X, K X convex bounded A { y w*clK; s,, *y 0 for n > 1 }.Iffor