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Keywords:
connected; locally connected; free topological group; condensation; connectification
Summary:
We study when a topological space has a weaker connected topology. Various sufficient and necessary conditions are given for a space to have a weaker Hausdorff or regular connected topology. It is proved that the property of a space of having a weaker Tychonoff topology is preserved by any of the free topological group functors. Examples are given for non-preservation of this property by ``nice'' continuous mappings. The requirement that a space have a weaker Tychonoff connected topology is rather strong, but we show that it is difficult to construct spaces which would contain no infinite subspaces with a weaker connected $T_{3{1\over 2}}$-topology.
References:
[1] Alas O.T., Tkačenko M.G., Tkachuk V.V., Wilson R.G.: Connectifying some spaces. Topology and its Applications, to appear. MR 1397942
[2] Arhangel'skii A.V., Ponomarev V.I.: General Topology in Problems and Exercises (in Russian). Nauka Publishing House, Moscow, 1974. MR 0239550
[3] Arhangel'skii A.V.: The structure and classification of topological spaces and cardinal invariants (in Russian). Uspehi Mat. Nauk 33.6 (1978), 29-84. MR 0526012
[4] Engelking R.: General Topology. PWN, Warszawa, 1977. MR 0500780 | Zbl 0684.54001
[5] Graev M.I.: Theory of topological groups, I (in Russian). Uspehi Mat. Nauk 5.2 (1950), 3-56. MR 0036245
[6] Miller A.W.: Special subsets of the real line. in: Handbook of Set-Theoretic Topology (Eds. K.Kunen, J.E.Vaughan), Elsevier S.P. B.V., 1984, pp.203-233. MR 0776624 | Zbl 0588.54035
[7] Rudin M.E.: Martin's axiom. in: Handbook of Mathematical Logic, edited by J.Barwise, Amsterdam, North Holland P.C., 1977, pp.491-501. MR 0457132
[8] Shapirovsky B.E.: On mappings onto Tychonoff cubes (in Russian). Uspehi Mat. Nauk 35.3 (1980), 122-130.
[9] Tkačenko M.G.: Examples of connected left separated spaces and topological groups. Acta Math., Acad. Sci. Hungar. 38.4 (1981), 257-261. MR 0647345
[10] Tkačenko M.G.: On group uniformities on the square of a space and extending pseudometrics. Bull. Austral. Math. Soc. 51.2 (1995), 309-335. MR 1322797
[11] Watson S., Wilson R.G.: Embeddings in connected spaces. Houston J. Math. 19.3 (1993), 469-481. MR 1242433 | Zbl 0837.54012
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