Results 1 to 10 of about 242 (55)
Compact mappings and s-mappings at subsets
Open Mathematics, 2022 Almost ss-mappings and almost compact mappings have been introduced and studied. In this article, we continue to research some questions related to the almost s-images (resp., almost compact images) of metric spaces.
Lin Shou, Ling Xuewei, He Wei
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so-metrizable spaces and images of metric spaces
Open Mathematics, 2021 so-metrizable spaces are a class of important generalized metric spaces between metric spaces and snsn-metrizable spaces where a space is called an so-metrizable space if it has a σ\sigma -locally finite so-network.
Yang Songlin, Ge Xun
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Ultradiversification of Diversities
Analysis and Geometry in Metric Spaces, 2020 In this paper, using the idea of ultrametrization of metric spaces we introduce ultradiversification of diversities. We show that every diversity has an ultradiversification which is the greatest nonexpansive ultra-diversity image of it.
Haghmaram Pouya, Nourouzi Kourosh
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Proof of a conjecture of Galvin
Forum of Mathematics, Pi, 2020 We prove that if the set of unordered pairs of real numbers is coloured by finitely many colours, there is a set of reals homeomorphic to the rationals whose pairs have at most two colours.
Dilip Raghavan, Stevo Todorcevic
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Restricting uniformly open surjections [PDF]
, 2017 We employ the theory of elementary submodels to improve a recent result by Aron, Jaramillo and Le Donne (Ann. Acad. Sci. Fenn. Math., to appear) concerning restricting uniformly open, continuous surjections to smaller subspaces where they remain ...
Kania, Tomasz, Rmoutil, Martin
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Bend sets, N‐sequences, and mappings
International Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 55, Page 2927-2936, 2004., 2004 The existence of an N‐sequence in a continuum is a common obstruction that implies nonsmoothness, noncontractibility, nonselectibility, and nonexistence of any mean. The aim of the present paper is to investigate if some variants of the concept of an N‐sequence also keep these properties. In particular, mapping properties of bend sets are studied.
Janusz J. Charatonik, Alejandro Illanes
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International Journal of Mathematics and Mathematical Sciences, Volume 30, Issue 10, Page 613-620, 2002., 2002 The concept of a terminal continuum introduced in 1973 by G. R. Gordh Jr., for hereditarily unicoherent continua is extended to arbitrary continua. Mapping properties of these two concepts are investigated. Especially the invariance of terminality under mappings satisfying some special conditions is studied.
Janusz J. Charatonik
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International Journal of Mathematics and Mathematical Sciences, Volume 27, Issue 11, Page 681-688, 2001., 2001 We study the open images of members of a countable family ℱ of dendrites. We show that only two members of ℱ are minimal and only one of them is unique minimal with respect to open mappings.
Janusz J. Charatonik
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Versatile asymmetrical tight extensions
Topological Algebra and its Applications, 2017 We show that the image of a q-hyperconvex quasi-metric space under a retraction is q-hyperconvex. Furthermore, we establish that quasi-tightness and quasi-essentiality of an extension of a T0-quasi-metric space are equivalent.
Otafudu Olivier Olela +1 more
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The lifting property for classes of mappings
International Journal of Mathematics and Mathematical Sciences, Volume 23, Issue 10, Page 717-722, 2000., 2000 The lifting property of continua for classes of mappings is defined. It is shown that the property is preserved under the inverse limit operation. The results, when applied to the class of confluent mappings, exhibit conditions under which the induced mapping between hyperspaces is confluent. This generalizes previous results in this topic.
Janusz J. Charatonik
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