On scattered spaces
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- by V. Kannan and M. Rajagopalan PDF
- Proc. Amer. Math. Soc. 43 (1974), 402-408 Request permission
Abstract:
We show that each $0$-dimensional Hausdorff space which is scattered can be mapped continuously in a one-to-one way onto a scattered $0$-dimensional Hausdorff space of the same weight as its cardinality. This gives an easier and a new proof of the fact that a countable regular space admits a coarser compact Hausdorff topology if and only if it is scattered. We also show that a $0$-dimensional, Lindelöf, scattered first-countable Hausdorff space admits a scattered compactification. In particular we give a more direct proof than that of Knaster, Urbanik and Belnov of the fact that a countable scattered metric space is a subspace of $[1,\Omega )$, and deduce a result of W. H. Young as a corollary.References
- V. K. Bel′nov, Compressions onto compacta, Dokl. Akad. Nauk SSSR 193 (1970), 506–509 (Russian). MR 0268859 V. Kannan and M. Rajagopalan, Countable topological spaces, Technical Publications of the Department of Mathematics, Madurai University (to appear).
- M. Katětov, On mappings of countable spaces, Colloq. Math. 2 (1949), 30–33. MR 39988, DOI 10.4064/cm-2-1-30-33
- B. Knaster and K. Urbanik, Sur les espaces complets séparables de dimension $0$, Fund. Math. 40 (1953), 194–202 (French). MR 60221, DOI 10.4064/fm-40-1-194-202 S. Mazurkiewicz and W. Sierpinski, Contribution à la topologies des ensembles d’enombrables, Fund. Math. 1 (1920), 17-27.
- S. Mrówka, M. Rajagopalan, and T. Soundararajan, A characterization of compact scattered spaces through chain limits (chain compact spaces), TOPO 72—general topology and its applications (Proc. Second Pittsburgh Internat. Conf., Pittsburgh, Pa., 1972; dedicated to the memory of Johannes H. de Groot), Lecture Notes in Math., Vol. 378, Springer, Berlin, 1974, pp. 288–297. MR 0375234
- R. S. Pierce, Existence and uniqueness theorems for extensions of zero-dimensional compact metric spaces, Trans. Amer. Math. Soc. 148 (1970), 1–21. MR 254804, DOI 10.1090/S0002-9947-1970-0254804-4
- C. Ryll-Nardzewski and R. Telgársky, On the scattered compactification, Bull. Acad. Polon. Sci. Sér. Sci. Math. Astronom. Phys. 18 (1970), 233–234 (English, with Russian summary). MR 263030
- Z. Semadeni, Sur les ensembles clairsemés, Rozprawy Mat. 19 (1959), 39 pp. (1959) (French). MR 107849 W. Sierpinski, Sur une propriété topologique des ensembles denombrables denses en soi, Fund. Math. 1 (1920), 11-16.
Additional Information
- © Copyright 1974 American Mathematical Society
- Journal: Proc. Amer. Math. Soc. 43 (1974), 402-408
- MSC: Primary 54D20; Secondary 54A25
- DOI: https://doi.org/10.1090/S0002-9939-1974-0334150-X
- MathSciNet review: 0334150