集值映射空间在紧开拓扑下的NO性质

本文讨论了点紧致的连续集值映射空间在赋予紧开拓扑下的某些拓扑性质,证明了:若X,Y为NO空间,则X到Y上的点紧致的连续集值映射族依紧开拓扑是NO空间,从而将Michael[1]的结论推广到更大的映射空间类上.     

集值映射空间上的■0特征1

应用k-网的概念证明了:若X,Y为■0空间且Y为局部紧的,则X到Y上满足条件(G)的点紧致的族连续集值映射族依紧开拓扑是■0空间.     

集值映射空间上的(ξ)0特征

应用k-网的概念证明了:若X,Y为(ξ)0空间且Y为局部紧的,则X到Y上满足条件(G)的点紧致的族连续集值映射族依紧开拓扑是(ξ)0空间.     

集值映射空间在紧开拓扑下的$\aleph_0$性质

本文讨论了点紧致的连续集值映射空间在赋予紧开拓扑下的某些拓扑性质,证明了:若$X,Y$为$\aleph_0$空间,则$X$到$Y$上的点紧致的连续集值映射族依紧开拓扑是$\aleph_{0}$空间,从而将Michael$^{[1]}$的结论推广到更大的映射空间类上.     

集值映射空间在紧开拓扑下的N性质(英文)

本文研究了点紧连续集值映射族在紧开拓扑下的N性质.利用cs-σ网方法获得了如下结果:若X是N0空间,Y是N空间,则C_k(X,Y)是N空间.该结论将J.A.Guthrie关于单值连续映射空间的结论推广到了集值映射空间上,并且改进了相关结论.     

集值映射空间上的基数函数

讨论了集值映射空间在赋予点态收敛拓扑或紧开拓扑下的权数,特征,网络权,稠密度等基数函数,利用自然映射,诱导映射和嵌入等方法将单值连续映射空间的有关结论推广到集值映射空间类上.     

集值映射空间上的仿紧性和 特征

本文研究了集值映射空间类上的仿紧性和 特征，利用k网的概念及Paul O＇Meara等人的结论，得到了点紧致连续集值映射族依紧开拓扑下的仿紧性和 特征的刻画．     

集值映射空间上的Tightness和Fan Tightness

本文讨论了连续集值映射空间在赋予点态收敛拓扑和紧开拓扑下的tightness和fan tightness, 将关于连续单值映射空间的某些结果推广到连续集值映射空间.     

集值映射空间上的仿紧性和(Ж)特征

本文研究了集值映射空间类上的仿紧性和(Ж)特征.利用k网的概念及Paul O'Meara等人的结论,得到了点紧致连续集值映射族依紧开拓扑下的仿紧性和(Ж)特征的刻画.     

集值Fredholm映射及其拓扑度

本文推广C~1-Fredholm映射的概念到上半连续集值映射的情形,并对零指标的集值Fredbolm映射及其集值紧摄动建立拓扑度理论。§1.集值Fredholm映射设X是C~0-Banach流形,模空间为Banach空间E,图册为A=     

Function-space compactifications of function spaces

If X and Y are Hausdorff spaces with X locally compact, then the compact-open topology on the set C(X,Y) of continuous maps from X to Y is known to produce the right function-space topology. But it is also known to fail badly to be locally compact, even when Y is locally compact. We show that for any Tychonoff space Y, there is a densely injective space Z containing Y as a densely embedded subspace such that, for every locally compact space X, the set C(X,Z) has a compact Hausdorff topology whose relative topology on C(X,Y) is the compact-open topology. The following are derived as corollaries: (1) If X and Y are compact Hausdorff spaces then C(X,Y) under the compact-open topology is embedded into the Vietoris hyperspace V(X×Y). (2) The space of real-valued continuous functions on a locally compact Hausdorff space under the compact-open topology is embedded into a compact Hausdorff space whose points are pairs of extended real-valued functions, one lower and the other upper semicontinuous. The first application is generalized in two ways.     

Some generalizations of Backʼs Theorem

The problem of the existence of jointly continuous utility functions is studied. A continuous representation theorem of Back [1] gives the existence of a continuous map from the space of total preorders topologized by closed convergence (Fell topology) to the space of utility functions with different choice sets (partial maps) endowed with a generalization of the compact-open topology. The commodity space is locally compact and second countable. Our results generalize Back?s Theorem to non-metrizable commodity spaces with a family of not necessarily total preorders. Precisely, we consider regular commodity spaces having a weaker locally compact second countable topology.     

集值映射空间上的自然映射(英文)

In this paper,we discuss the continuities of some natural mappings on pointcompact continuous set-valued mapping spaces with compact-open topology and obtain the properties of set-valued injective mappings,set-valued diagonal mappings,induced mappings,set-valued evaluation mappings,set-valued topological sum mappings and set-valued topological product mappings.     

Versions of separability in bitopological spaces

We study selective versions of separability in bitopological spaces. In particular, we investigate these properties in function spaces endowed with the topology of pointwise convergence and the compact-open topology.     

On the compact-open and admissible topologies

It is known (see, for example, [H. Render, Nonstandard topology on function spaces with applications to hyperspaces, Trans. Amer. Math. Soc. 336 (1) (1993) 101-119; M. Escardo, J. Lawson, A. Simpson, Comparing cartesian closed categories of (core) compactly generated spaces, Topology Appl. 143 (2004) 105-145; D.N. Georgiou, S.D. Iliadis, F. Mynard, Function space topologies, in: Open Problems in Topology 2, Elsevier, 2007, pp. 15-23]) that the intersection of all admissible topologies on the set C(Y,Z) of all continuous maps of an arbitrary space Y into an arbitrary space Z, is always the greatest splitting topology (which in general is not admissible). The following, interesting in our opinion, problem is arised: when a given splitting topology (for example, the compact-open topology, the Isbell topology, and the greatest splitting topology) is the intersection of k admissible topologies, where k is a finite number. Of course, in this case this splitting topology will be the greatest splitting.In the case, where a given splitting topology is admissible the above number k is equal to one. For example, if Y is a locally compact Hausdorff space, then k=1 for the compact-open topology (see [R.H. Fox, On topologies for function spaces, Bull. Amer. Math. Soc. 51 (1945) 429-432; R. Arens, A topology for spaces of transformations, Ann. of Math. 47 (1946) 480-495; R. Arens, J. Dugundji, Topologies for function spaces, Pacific J. Math. 1 (1951) 5-31]). Also, if Y is a corecompact space, then k=1 for the Isbell topology (see [P. Lambrinos, B.K. Papadopoulos, The (strong) Isbell topology and (weakly) continuous lattices, in: Continuous Lattices and Applications, in: Lect. Notes Pure Appl. Math., vol. 101, Marcel Dekker, New York, 1984, pp. 191-211; F. Schwarz, S. Weck, Scott topology, Isbell topology, and continuous convergence, in: Lect. Notes Pure Appl. Math., vol. 101, Marcel Dekker, New York, 1984, pp. 251-271]).In [R. Arens, J. Dugundji, Topologies for function spaces, Pacific J. Math. 1 (1951) 5-31] a non-locally compact completely regular space Y is constructed such that the compact-open topology on C(Y,S), where S is the Sierpinski space, coincides with the greatest splitting topology (which is not admissible). This fact is proved by the construction of two admissible topologies on C(Y,S) whose intersection is the compact-open topology, that is k=2.In the present paper improving the method of [R. Arens, J. Dugundji, Topologies for function spaces, Pacific J. Math. 1 (1951) 5-31] we construct some other non-locally compact spaces Y such that the compact-open topology on C(Y,S) is the intersection of two admissible topologies. Also, we give some concrete problems concerning the above arised general problem.     

“Boundedly generated topological spaces”

The new class of Boundedly generated topological spaces (or l-spaces) is defined and studied by topological methods. It is shown that it is strictly broader than the class of (Hausdorff) compactly generated spaces (or k-spaces) and also that l-spaces possess many of the nice properties of k-spaces e.g. they are closed under the formation of disjoint unions, quotients, direct limits e.t.c. The topology of uniform convergence on boundeda is also studied and in general, it is shown to be strictly finer than the compact-open topology on the space of continuous functions.