Deux exemples de pathologies pour les groupes topologiques non localement compacts (Q1073192)
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scientific article; zbMATH DE number 3944163
| Language | Label | Description | Also known as |
|---|---|---|---|
| English | Deux exemples de pathologies pour les groupes topologiques non localement compacts |
scientific article; zbMATH DE number 3944163 |
Statements
Deux exemples de pathologies pour les groupes topologiques non localement compacts (English)
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1985
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The author provides counterexamples to parts of exercise 2, {\S} 1, chap. 5, of \textit{N. Bourbaki} [Topologie générale, Nouv. éd. (1974; Zbl 0337.54001)] showing that the second part of b) as well as c), d), and e) are incorrect, while the first part of b) as well as a) and f) are correct. Specifically, the author shows that (1) there is a Hausdorff topology on \({\mathbb{R}}\) (resp. \({\mathbb{Z}})\) consistent with the additive group structure and strictly coarser than the usual topology (resp. non- discrete) which is not precompact, and (2) there is a complete metrizable abelian group which does not have as neutral component the closure of the subgroup generated by all one-parameter subgroups.
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precompact topological group
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counterexamples
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complete metrizable abelian group
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neutral component
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