共查询到20条相似文献,搜索用时 15 毫秒
1.
Ignacio Villanueva 《Czechoslovak Mathematical Journal》2004,54(2):373-378
We use polymeasures to characterize when a multilinear form defined on a product of C(K, X) spaces is integral. 相似文献
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Jachymski showed that the set $$\left\{ {(x,y) \in {{\rm{c}}_0} \times {{\rm{c}}_0}:\left( {\sum\limits_{i = 1}^n {\alpha (i)x(i)y(i)} } \right)_{n = 1}^\infty {\rm{ is bounded}}} \right\}$$ is either a meager subset of c 0 × c 0 or is equal to c 0 × c 0. In the paper we generalize this result by considering more general spaces than c 0, namely C 0(X), the space of all continuous functions which vanish at infinity, and C b (X), the space of all continuous bounded functions. Moreover, we replace the meagerness by σ-porosity. 相似文献
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Mehdi Parsinia 《Quaestiones Mathematicae》2018,41(5):675-682
Let X be a Tychono? space and A(X) be a subring of C(X) containing C?(X). We introduce the notion of -ideal in A(X). It is observed that the class of -ideals contains the class of zA-ideals and is contained in the class of z-ideals of A(X). These containments may be proper. It turns out that coincidence of z-ideals of A(X) with -ideals characterizes intermediate C-rings of C(X). 相似文献
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Summary In this article the zero-divisor graph Γ(C(X)) of the ring C(X) is studied. We associate the ring properties of C(X), the graph properties of Γ(C(X)) and the topological properties of X. Cycles in Γ(C(X)) are investigated and an algebraic and a topological characterization is given for the graph Γ(C(X)) to be triangulated or hypertriangulated. We have shown that the clique number of Γ(C(X)), the cellularity of X and the Goldie dimension of C(X) coincide. It turns out that the dominating number of Γ(C(X)) is between the density and the weight of X. Finally we have shown that Γ(C(X)) is not triangulated and the set of centers of Γ(C(X)) is a dominating set if and only if the set of isolated points of X is dense in X if and only if the socle of C(X) is an essential ideal. 相似文献
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本文研究了连续函数代数C(X)与某个C*-代数 A的张量积C(X) A的自同构群.当 A是有单位元且具有平凡中心的C*-代数时,本文完全刻划了C(X) A的自同构群.利用AF-代数的K-理论,本文还刻划了当X是全不连通的紧致Hausdorff空间时,C(X)与紧算子理想的张量积的自同构群. 相似文献
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This is a study of the dual space of continuous linear functionals on the function space Cps(X) with a natural norm inherited from a larger Banach space. Here ps denotes the pseudocompact-open topology on C(X), the set of all real-valued continuous functions on a Tychonoff space X. The lattice structure and completeness of this dual space have been studied. Since this dual space is inherently related
to a space of measures, the measure-theoretic characterization of this dual space has been studied extensively. Due to this
characterization, a special kind of topological space, called pz-space, has been studied. Finally the separability of this dual space has been studied.
相似文献
8.
Dedicated to Professor H. G. Tillmann on the occasion of his 65th birthday 相似文献
9.
Ignacio Villanueva 《Czechoslovak Mathematical Journal》2004,54(1):31-54
Given Banach spaces X, Yand a compact Hausdorff space K, we use polymeasures to give necessary conditions for a multilinear operator from C(K, X) into Yto be completely continuous (resp. unconditionally converging). We deduce necessary and sufficient conditions for Xto have the Schur property (resp. to contain no copy of c
0), and for Kto be scattered. This extends results concerning linear operators. 相似文献
10.
J. M. Domínguez 《Acta Mathematica Hungarica》2002,95(1-2):29-35
Let
be the algebra of all real-valued continuous functions on a completely regular space X, and
the subalgebra of bounded functions. We show that the space of real maximal ideals of an intermediate algebra between
and
is a
-embedded closed subspace of the product of
with a product of copies of the real line. We make use of this embedding to provide a new characterization of the intermediate algebras that are closed under countable composition, and to exhibit an example of an intermediate algebra on
that is closed under countable composition but not isomorphic to any
. 相似文献
11.
R. A. McCoy 《Mathematica Slovaca》2013,63(1):143-166
This study looks at some subgroups of the group H(C(X)) of homeomorphisms on the space C(X) of continuous real-valued functions on a topological space X, where C(X) has the compact-open topology. The main result shows that, for certain spaces X, the subgroup of H(C(X)) generated by the algebraic and vertical homeomorphisms on C(X) is dense in H(C(X)) with the pointwise topology. Also, for X equal to the unit interval, a subgroup of H(C(X)) is developed using integration of the members of C(X), and this subgroup is used as an example and to illustrate certain properties that subgroups of H(C(X)) can have. 相似文献
12.
We prove that the space C
c
(X) of the real-valued continuous functions with the compact-open topology is quasi-Souslin iff it is K-analytic. This implies that C
c
(X) is K-analytic iff it is dominated by the irrationals.
Partially supported by the project MTM2005-01182 of the Spanish Ministry of Education and Science, co-financed by the European
Community (Feder projects). 相似文献
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N. V. Veličko 《Georgian Mathematical Journal》1995,2(6):653-657
Some relations between cardinal invariants ofX andC(X) are established in the weak topology, whereC(X) is the space of continuous real-valued functions onX in the compact-open topology. 相似文献
15.
Ralf Hollstein 《manuscripta mathematica》1982,38(1):41-58
Let C(X,E) be the vector space of all continuous functions on a completely regular Hausdorff space X with values in a locally convex space E, equipped with the compact-open topology. In this note it will be shown that for many classes of locally convex spaces K C(X,E) lies in K if and only if C(X)=C(X,¦K) (¦K=¦R or C) and E belong to K. This is valid for the classes K. of all metrizable, normed, (DF)-, -locally topological, separable, quasi-complete, complete, nuclear, Schwartz, semi-Montel, Montel, semi-reflexive, reflexive and quasi-normable locally convex spaces, respectively. But in general C(X,E) is not quasi-barrelled, barrelled and bornological, respectively, if C(X) and E belong to the same class. We shall give sufficient conditions for C(X,E) to be quasi-barrelled and barrelled, respectively.Herrn Professor Gottfried Köthe zum 75. Geburtstag gewidmet 相似文献
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《数学物理学报(B辑英文版)》2016,(5)
A bounded linear operator T on a complex Hilbert space H is called(n, k)-quasi-*-paranormal if ║T~(1+n)(T~kx) ║~(1/(1+n))║ T~kx║~(n/(1+n))≥║ T*(T~kx)║ for all x ∈ H,where n, k are nonnegative integers. This class of operators has many interesting properties and contains the classes of n-*-paranormal operators and quasi-*-paranormal operators. The aim of this note is to show that every Riesz idempotent E_λ with respect to a non-zero isolated spectral point λ of an(n, k)-quasi-*-paranormal operator T is self-adjoint and satisfies ran E_λ= ker(T- λ) = ker(T- λ)*. 相似文献