We survey several applications of Simons’ inequality and state related open problems. We show that if a Banach space X has a strongly sub-differentiable norm, then every bounded weakly closed subset of X is an intersection of finite union of balls.
We prove the continuity in norm of the translation operator in the Musielak-Orlicz spaces. An application to the convergence in norm of approximate identities is given, whereby we prove density results of the smooth functions in , in both the modular and norm topologies. These density results are then applied to obtain basic topological properties.
In [2] W. Banaszczyk introduced nuclear groups, a Hausdorff variety of abelian topological groups which is generated by all nuclear vector groups (cf. 2.3) and which contains all nuclear vector spaces and all locally compact abelian groups. We prove in 5.6 that the Hausdorff variety generated by all nuclear vector spaces and all locally compact abelian groups (denoted by 𝒱₁) is strictly smaller than the Hausdorff variety of all nuclear groups (denoted by 𝒱₂). More precisely,...
We survey some recent developments in the theory of Fréchet spaces and of their duals. Among other things, Section 4 contains new, direct proofs of properties of, and results on, Fréchet spaces with the density condition, and Section 5 gives an account of the modern theory of general Köthe echelon and co-echelon spaces. The final section is devoted to the developments in tensor products of Fréchet spaces since the negative solution of Grothendieck?s ?problème des topologies?.
A closed convex set in a local convex topological Hausdorff spaces is called locally nonconical (LNC) if for every there exists an open neighbourhood of such that . A set is local cylindric (LC) if for , , there exists an open neighbourhood of such that (equivalently: ) is a union of open segments parallel to . In this paper we prove that these two notions are equivalent. The properties LNC and LC were investigated in [3], where the implication was proved in general, while...