Abstract
In this paper, we examine categorical and cardinal properties of hyperspaces with finite number of components. We prove that the functor Cn : Comp → Comp is not normal, i.e., it does not preserve epimorphisms of continuous mappings. We also discuss the density, the caliber, and the Shanin number of the space Cn(X).
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P. S. Alexandroff and P. S. Urysohn, Memoire sur les espaces topologiques compacts, Verh. Akad. Wetensch. Amsterdam (1929), No. 14.
R. B. Beshimov, “Weak density and hyperspaces,” Uzbek. Mat. Zh., 4, 3–7 (2000).
R. B. Beshimov, “A note on weakly separable spaces,” Math. Moravica, 6, 9–19 (2002).
R. B. Beshimov, “Some cardinal properties of topological spaces connected with weakly density,” Methods Funct. Anal. Topol., 10, No. 3, 17–22 (2004).
J. Camargo and S. Macias, “Quotients of n-fold hyperspaces,” Topol. Appl., 197, 154–166 (2016).
R. Engelking, General Topology, Heldermann, Berlin (1989).
V. V. Fedorchuk and V. V. Filippov, General Topology. Fundamental Constructions [in Russian], Moscow (2014).
Y. Hattory, “Order and topological structures of posets of the formal balls on metric spaces,” Mem. Fac. Sci. Eng. Shimane Univ. Ser. B. Math. Sci., No. 43, 13–26 (2010).
S. Macias, “On n-fold hyperspaces of continua,” Glas. Mat., 64, No. 44, 479–492 (2009).
E. V. Shchepin, “Functors and uncountable powers of compacta,” Usp. Mat. Nauk, 36, No. 3 (219), 3–62 (1981).
R. H. Sorgenfrey, “On the topological product of paracompact spaces,” Bull. Am. Math. Soc., 53, 631–632 (1947).
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Translated from Itogi Nauki i Tekhniki, Seriya Sovremennaya Matematika i Ee Prilozheniya. Tematicheskie Obzory, Vol. 144, Proceedings of the Conference “Problems of Modern Topology and Its Applications” (May 11–12, 2017), Tashkent, Uzbekistan, 2018.
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Beshimov, R.B., Mamadaliev, N.K. & Eshtemirova, S.K. Categorical and Cardinal Properties of Hyperspaces with a Finite Number of Components. J Math Sci 245, 390–397 (2020). https://doi.org/10.1007/s10958-020-04701-8
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DOI: https://doi.org/10.1007/s10958-020-04701-8