弱和强可逆空间

IF 0.5 4区 数学 Q3 MATHEMATICS
Miloš S. Kurilić
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引用次数: 0

摘要

拓扑空间X是可逆的,只要每个连续双射(凝聚)f:X→X是同胚;弱可逆的当Y是空间且存在缩聚f:X→Y和g:Y→X时,存在同胚h:X→Y;如果每个双射f:X→X是同胚。证明了弱可逆非可逆空间与序列空间不相交,其中每个序列最多有一个极限(例如包含可度量空间)。另一方面,强可逆拓扑类只包含离散拓扑、反离散拓扑和有限拓扑的自然推广。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Weakly and strongly reversible spaces
A topological space X is reversible iff each continuous bijection (condensation) f:XX is a homeomorphism; weakly reversible iff whenever Y is a space and there are condensations f:XY and g:YX, there is a homeomorphism h:XY; strongly reversible iff each bijection f:XX is a homeomorphism. We show that the class of weakly reversible non-reversible spaces is disjoint from the class of sequential spaces in which each sequence has at most one limit (containing e.g. metrizable spaces). On the other hand, the class of strongly reversible topologies contains only discrete topologies, antidiscrete topologies and natural generalizations of the cofinite topology.
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来源期刊
CiteScore
1.20
自引率
33.30%
发文量
251
审稿时长
6 months
期刊介绍: Topology and its Applications is primarily concerned with publishing original research papers of moderate length. However, a limited number of carefully selected survey or expository papers are also included. The mathematical focus of the journal is that suggested by the title: Research in Topology. It is felt that it is inadvisable to attempt a definitive description of topology as understood for this journal. Certainly the subject includes the algebraic, general, geometric, and set-theoretic facets of topology as well as areas of interactions between topology and other mathematical disciplines, e.g. topological algebra, topological dynamics, functional analysis, category theory. Since the roles of various aspects of topology continue to change, the non-specific delineation of topics serves to reflect the current state of research in topology. At regular intervals, the journal publishes a section entitled Open Problems in Topology, edited by J. van Mill and G.M. Reed. This is a status report on the 1100 problems listed in the book of the same name published by North-Holland in 1990, edited by van Mill and Reed.
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