共查询到20条相似文献,搜索用时 15 毫秒
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Mieczyslaw Mastylo 《Mathematische Nachrichten》1988,137(1):27-34
In this paper we study interpolation spaces generated by some interpolation functors. We show that under some conditions for Banach couples X and Y the spaces dual to the orbits of elements are Gelfand—Philips spaces. Consequently, the ideal of nuclear operators from X to Y contains a copy of l1. We give also an interpolation theorem for limited operators. 相似文献
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Lotfi Lassoued 《东北数学》1998,(2)
ARemarkontheWeakTopologyandtheDegreeLotfiLassoued(Laboratoired'AnalyseNumériqueUniversitéPierreetMarieCurie4,placeJusieu,7525... 相似文献
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本文证明了这样一个主要结果:设(K,S)和(K,S)都是亚序域,且(K,S)是(K,S)的有限生成扩张,则当K在K上是超越时,(K,S)具有弱Hilbert性质.这一结果否定地回答了作者在文献[1]中所提的一个公开问题.此外,一些关于弱Hilbert性质的结果被建立. 相似文献
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On Borel Sets in Function Spaces with the Weak Topology 总被引:1,自引:0,他引:1
It is proved that the duality map ,:(, weak)x(()*, weak*)R isnot Borel. More generally, the evaluation e:(C)(K),x KR, e(f,x) = f(x), is not Borel for any function space C(K) on a compactF-space. It is also shown that a non-coincidence of norm-Boreland weak-Borel sets in a function space does not imply thatthe duality map is non-Borel. 相似文献
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De Maria Jose L.; Rodriguez-Salinas Baltasar 《Bulletin London Mathematical Society》1993,25(6):577-581
In this paper, Schachermayer's Theorem [6] is improved by showingthat a WCG Banach space whose density is of measure zero isa Radon space with the weak topology (weak-Radon). We also considerother conditions under which a Banach space is a weak-Radonspace. 相似文献
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A. A. Uspenskii 《Proceedings of the Steklov Institute of Mathematics》2018,301(1):164-172
We consider the problem of constructing resolving sets for a differential game or an optimal control problem based on information on the dynamics of the system, control resources, and boundary conditions. The construction of largest possible sets with such properties (the maximal stable bridge in a differential game or the controllability set in a control problem) is a nontrivial problem due to their complicated geometry; in particular, the boundaries may be nonconvex and nonsmooth. In practical engineering tasks, which permit some tolerance and deviations, it is often admissible to construct a resolving set that is not maximal. The constructed set may possess certain characteristics that would make the formation of control actions easier. For example, the set may have convex sections or a smooth boundary. In this context, we study the property of stability (weak invariance) for one class of sets in the space of positions of a differential game. Using the notion of stability defect of a set introduced by V.N. Ushakov, we derive a criterion of weak invariance with respect to a conflict control dynamic system for cylindrical sets. In a particular case of a linear control system, we obtain easily verified sufficient conditions of weak invariance for cylindrical sets with ellipsoidal sections. The proof of the conditions is based on constructions and facts of subdifferential calculation. An illustrating example is given. 相似文献
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We present some result of lifting of the Gelfand Phillips property from Banach spacesE andF to Banach spaces of compact operators and of Bochner integrable functions. Moreover we studyC(K) spaces possessing the same property. In the last section we prove some result concerning the so called three space problem for the Gelfand Phillips property too. 相似文献
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利用区域的变分,在一定条件下,讨论拟线性椭圆型方程-div A(x,u,Du)=f(x)弱解关于区域的稳定性. 相似文献
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Abhishek Banerjee 《代数通讯》2013,41(3):1067-1077
The object of this article is to study the regularity properties of elements of a ring with respect to a given ideal I. As expected, several concepts that are equivalent in the case of I = R turn out to be distinct for a general ideal I and we consider the relations between these properties. In particular, we replace the set of units U(R) of the ring R by the set U I (R) = {u|uI = Iu = I} and use these “relative units” to obtain generalizations of notions such as stable range and unit-regularity. We also see that on assuming the set of “relative units” to have no zero divisors, we can obtain several interesting results. 相似文献
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We construct a σ-ideal of subsets of the Cantor space which is productive but does not have the Weak Fubini Property. In the
construction we use a combinatorial lemma which is of its own interest. 相似文献
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Picavet 《Semigroup Forum》2008,67(1):76-96
Abstract. We introduce the class of localizable monoids. It contains inverse monoids. Then we define localizations of monoids with
respect to localizable submonoids of their monoid of endomorphisms. These constructions can be applied to a category of left
modules or to a category of A -rings. As a result, we are able to invert endomorphisms within the original category, unlike inversive localizations of
Cohn's type which need a base change. 相似文献
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We present a simple proof of the fact that every countable group is weak Rohlin, that is, there is in the Polish space A ofmeasure preserving -actions an action T whose orbit in A underconjugations is dense. In conjunction with earlier results thisin turn yields a new characterization of non-Kazhdan groupsas those groups which admit such an action T which is also ergodic.2000 Mathematics Subject Classification 28D15, 22D10. 相似文献