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1.
Let Y ? ?N be a possibly singular projective variety, defined over the field of complex numbers. Let X be the intersection of Y with h general hypersurfaces of sufficiently large degrees. Let d > 0 be an integer, and assume that dimY = n + h and dimYsing ≤ min {d + h ? 1, n ? 1}. Let Z be an algebraic cycle on Y of dimension d + h, whose homology class in H2(d+h)(Y; ?) is nonzero. In the present article, we prove that the restriction of Z to X is not algebraically equivalent to zero. This is a generalization to the singular case of a result due to Nori in the case Y is smooth. As an application we provide explicit examples of singular varieties for which homological equivalence is different from the algebraic one. 相似文献
2.
Qing MENG 《数学年刊B辑(英文版)》2019,40(3):429-438
In this paper, the author first introduces the concept of
generalized algebraic cone metric spaces and some elementary results
concerning generalized algebraic cone metric spaces. Next, by using
these results, some new fixed point theorems on generalized
(complete) algebraic cone metric spaces are proved and an example is
given. As a consequence, the main results generalize the
corresponding results in complete algebraic cone metric spaces and
generalized complete metric spaces. 相似文献
3.
本文主要考虑度量空间中拟双曲一致域与拟对称映射之间的关系,并证明了度量空间中拟双曲一致域在拟对称映射下仍然是保持不变的. 相似文献
4.
Approximation of Metric Spaces by Partial Metric Spaces 总被引:1,自引:0,他引:1
Reinhold Heckmann 《Applied Categorical Structures》1999,7(1-2):71-83
Partial metrics are generalised metrics with non-zero self-distances. We slightly generalise Matthews' original definition of partial metrics, yielding a notion of weak partial metric. After considering weak partial metric spaces in general, we introduce a weak partial metric on the poset of formal balls of a metric space. This weak partial metric can be used to construct the completion of classical metric spaces from the domain-theoretic rounded ideal completion. 相似文献
5.
本文讨论了布尔函数的重量与代数免疫性之间的关系,给出了判断布尔函数是否有低次零化子的一个充分条件,并对由几类传统的构造方法所获得的布尔函数的代数免疫性进行了分析. 相似文献
6.
V. Indumathi 《Set-Valued Analysis》2007,15(3):239-250
We prove that if X is a Banach space and Y is a proximinal subspace of finite codimension in X such that the finite dimensional annihilator of Y is polyhedral, then the metric projection from X onto Y is lower Hausdorff semi continuous. In particular this implies that if X and Y are as above, with the unit sphere of the annihilator space of Y contained in the set of quasi-polyhedral points of X
*, then the metric projection onto Y is Hausdorff metric continuous.
Partially supported under project DST/INT/US-NSF/RPO/141/2003. 相似文献
7.
WANG Gui-xia 《数学季刊》2007,22(4):602-606
In this paper we give the proof about the equivalence of the complete Einstein- Kahler metric and the Bergman metric on Cartan-Hartogs domain of the third type. And we obtain the method of getting the equivalence of two metrics. 相似文献
8.
Let (X
i
d
i
), i=1,2, be proper geodesic hyperbolic metric spaces. We give a general construction for a 'hyperbolic product' X
1×
h
X
2 which is itself a proper geodesic hyperbolic metric space and examine its boundary at infinity. 相似文献
9.
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11.
It is proved that under certain conditions the group K
n
(X) of a smooth projective variety X over a field F is a natural direct summand of K
n
(A) for some separable F-algebra A. As an application we study the K-groups of toric models and toric varieties. A presentation in terms of generators and relations of the groupK
0(T) for an algebraic torus T is given. 相似文献
12.
广义度量空间和偏序集都具有函数空间.而函数空间的存在为数学构造和计算提供了很大方便.本文还讨论了广义度量空间和偏序集之间的相互转化问题. 相似文献
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17.
第四类Caftan-Hartogs域上Bergman度量与Einstein-Kahler度量等价 总被引:1,自引:0,他引:1
In this paper,we discuss the invariaut complete metric on the Cartan-Hartogs domain of the fourth type.Firstly,we find a new invariant complete metric,and prove the equivalence between Bergman metric and the new metric;Secondly,the Ricci curvature of the new metric has the super bound and lower bound;Thirdly,we prove that the holomorphic sectional curvature of the new metric has the negative supper bound;Finally,we obtain the equivalence between Bergman metric and Einstein-Kahler metric on the Cartan-Hartogs domain of the fourth type. 相似文献
18.
19.
Basic Theory in Construction of Boolean Functions with Maximum Possible Annihilator Immunity 总被引:9,自引:0,他引:9
So far there is no systematic attempt to construct Boolean functions with maximum annihilator immunity. In this paper we present
a construction keeping in mind the basic theory of annihilator immunity. This construction provides functions with the maximum
possible annihilator immunity and the weight, nonlinearity and algebraic degree of the functions can be properly calculated
under certain cases. The basic construction is that of symmetric Boolean functions and applying linear transformation on the
input variables of these functions, one can get a large class of non-symmetric functions too. Moreover, we also study several
other modifications on the basic symmetric functions to identify interesting non-symmetric functions with maximum annihilator
immunity. In the process we also present an algorithm to compute the Walsh spectra of a symmetric Boolean function with O(n2) time and O(n) space complexity.
We use the term “Annihilator Immunity” instead of “Algebraic Immunity” referred in the recent papers [3–5, 9, 18, 19]. Please
see Remark 1 for the details of this notational change 相似文献
20.
Some topological properties of cone metric spaces are discussed and proved that every cone metric space (X, d) is complete if and only if every family of closed subsets of X which has the finite intersection property and which for every c ε E, 0 〈〈 c contains a set of diameter less that c has non-empty intersection. 相似文献