The category of Urysohn spaces is not cowellpowered |
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Authors: | Joachim Schröder |
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Affiliation: | Department of Mathematics, Free University, Berlin, West Germany |
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Abstract: | It is shown that the category of Urysohn spaces and continuous maps is not cowellpowered. To this end we will construct for each ordinal number β a Urysohn space Yβ with card and a continuous map from the rationals into Yβ. It turns out that is an external monomorphism in the category of Hausdorff spaces and an epimorphism in the category of Urysohn spaces. |
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Keywords: | 18A40 54A10 54B99 |
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