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(HM)-Spaces and Measurable Cardinals

Published online by Cambridge University Press:  20 November 2018

José A. Facenda Aguirre*
Affiliation:
Facultad de Matemáticas Universidad de Sevilla C) Tarfia S/N. Sevilla (12), Spain
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Abstract

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A locally convex space E is called an (HM)-space if E has invariant nonstandard hulls. In this paper we prove that if E is an (HM)-space, then E is a T(μ)-space, where μ is the first measurable cardinal. This is equivalent to say that in an (HM)-space, with dim(E)≧μ, does not exist a continuous norm. With this result, we prove that there exists an inductive semi-reflexive space E such that the bounded sets in E are finite-dimensional but E is not an (HM)-space. Thus, we answer negatively to an open problem raised up by Bellenot. In this paper, we do not use nonstandard analysis.

Keywords

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1984

References

1. Bellenot, S. F., On nonstandard hulls of convex spaces, Canad. J. Math. vol. XXVIII, 1 (1976), 141-147.Google Scholar
2. Berezanskii, I. A., Inductively reflexive locally convex spaces, Soviet Math. Doklady, 9(2) (1969), 1080-1082.Google Scholar
3. Comfort, W. W. and Negrepontis, S., The theory of ultrafilters, (Springer-Verlag, New York, 1974).Google Scholar
4. Diestel, J., Morris, S. A. and Saxon, S. A., Varieties of linear topological spaces. Trans. Amer. Math. Soc. 172 (1972), 207-230.Google Scholar
5. Henson, C. W. and Moore, L. C. Jr, The nonstandard theory of topological vector spaces, Trans. Amer. Math. Soc. 172 (1972), 405-435.Google Scholar
6. Henson, C. W. and Moore, L. C., Invariance of the nonstandard hulls of locally convex spaces, Duke Math. J. 40 (1973), 193-206.Google Scholar
7. Kothe, G., Topological Vector Spaces 1, (Springer-Verlag, New York, 1969).Google Scholar
8. Pfister, H., Uber Das Gewicht Und Den Uberdeckungstyp Von Uniformen Raumen Und Einige Formen Des Satzes Von Banach-Steinhaus, Manuscripta Math. 20 (1977), 51-72.Google Scholar
9. Stroyan, K. D. and Luxemburg, W. A. J., Introduction to the theory of infinitesimals, (Academic Press, New York, 1976).Google Scholar