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Weak Cauchy sequences in normed linear spaces

Published online by Cambridge University Press:  24 October 2008

D. J. H. Garling
Affiliation:
St John's College, Cambridge

Extract

It follows from the Krein-Milman theorem that (c0) is not isomorphic to the dual of a Banach space. Using a technique due to Banach ((4), page 194) we shall extend this result to show that if a subspace of (c0) is isomorphic to the dual of a normed linear space, then it is finite dimensional (Proposition 1). Using this result, we shall show that if E is a normed linear space, the unit ball of which is contained in the closed absolutely convex cover of a weak Cauchy sequence, then Eis finite dimensional (Proposition 2). This result has applications to the Banach-Dieudonné theorem, and to the theory of two-norm spaces.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1964

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References

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