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RESEARCH PRODUCT

Some Questions of Heinrich on Ultrapowers of Locally Convex Spaces

Antonio GalbisAlfred Peris

subject

Discrete mathematicsConvex analysisMathematics::Functional AnalysisPure mathematicsSequenceGeneral MathematicsBanach spaceConvex setUltraproductSpace (mathematics)Mathematics::LogicBounded functionLocally convex topological vector spaceMathematics

description

In this note we treat some open problems of Heinrich on ultrapowers of locally convex spaces. In section 1 we investigate the localization of bounded sets in the full ultrapower of a locally convex space, in particular the coincidence of the full and the bounded ultrapower, mainly concentrating in the case of (DF)-spaces. In section 2 we provide a partial answer to a question of Heinrich on commutativity of strict inductive limits and ultrapowers. In section 3 we analyze the relation between some natural candidates for the notion of superreflexivity in the setting of Frechet spaces. We give an example of a Frechet-Schwartz space which is not the projective limit of a sequence of superreflexive Banach spaces.

https://doi.org/10.1002/mana.19931610120