共查询到20条相似文献,搜索用时 64 毫秒
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群G中一个元素x称作是G中的一个换位元,如果x=aba~(-1)b~(-1),这里由G中一切换位元所生成的子群称为G的换位子群,通常记作G'。如果G为非交换单群,则G=G'。因而G中每个元素均可表为有限个换位元的乘积。在[1]中O.Ore提出了如下的猜想:在一个有限非交换单群中,每一个元素都可以表成换位元的形式。在同一文 相似文献
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设群 G 是有限群,a,b∈G,称 a~(-1)b~(-1)ab 为 G 的一个换位元.由 G 的全部换位元生成的子群 G′称为 G 的换位子群.很明显,G′是 G 的正规子群.当 G 是非交换单群时,G′=G,这说明,任何一个非交换单群 G 的每个元素都是 G 的换位元的乘积.但是否就 相似文献
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12参双参数矩形板元的误差估计 总被引:1,自引:0,他引:1
双参数方法是构造高阶问题有限元的有效方法.以此方法构造的双参数元是一种非标准元,以往文献中只证明了它的收敛性.此文针对具体12参双参数矩形板元给出它的误差估计式,并分析了节点参数的扰动量.文中的分析方法也适合于其它双参数矩形板元的误差估计. 相似文献
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本文从理论上比较了四边形四节点元和四边形八节点元的h-收敛性,得出八节点元较四节点元有较快收敛率的结论,并通过算例进行了验证。 相似文献
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O. A. Alekseeva 《Algebra and Logic》2006,45(1):1-11
It is proved that if G is a finite group with an element order set as in the simple group 3D4(q), where q is even, then the commutant of G/F(G) is isomorphic to 3D4(q) and the factor group G/G′ is a cyclic {2, 3}-group.
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Translated from Algebra i Logika, Vol. 45, No. 1, pp. 3–19, January–February, 2006. 相似文献
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E. I. Timoshenko 《Siberian Mathematical Journal》2013,54(5):926-930
We set forth an algorithm for computing the commutator width of an arbitrary element in the commutant of a discrete wreath product of free abelian groups. 相似文献
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In this paper a new lifting interpolation problem is introduced and an explicit solution is given. The result includes the commutant lifting theorem as well as its generalizations in [27] and [2]. The main theorem yields explicit solutions to new natural variants of most of the metric constrained interpolation problems treated in [9]. It is also shown that via an infinite dimensional enlargement of the underlying geometric structure a solution of the new lifting problem can be obtained from the commutant lifting theorem. However, the new setup presented obtained from the commutant lifting theorem. However, the new setup presented in this paper appears to be better suited to deal with interpolations problems from systems and control theory than the commutant lifting theorem.Dedicated to Israel Gohberg, as a token of admiration for his inspiring work in analysis and operator theory, with its far reaching applications, in friendship and with great affection. 相似文献
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The commutant modulo compacts, or essential commutant, of a reflexive algebra with commutative subspace lattice is a C* algebra which is the sum of the compact operators in L(H) and a C* subalgebra of the core. We give a characterization of the essential commutant of a separably acting CSL algebra in terms of properties of the spectral measure of an operator in the intersection of the essential commutant and the core. This is used to determine some sufficient conditions on the lattice for when the essential commutant is norm generated by the projections it contains. 相似文献
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Mark Greer 《代数通讯》2017,45(5):2222-2237
We define a variety of loops called semiautomorphic, inverse property loops that generalize Moufang and Steiner loops. We first show an equivalence between a previously studied variety of loops. Next we extend several known results for Moufang and Steiner loops. That is, the commutant is a subloop and if a is in the commutant, then a2 is a Moufang element, a3 is a c-element and a6 is in the center. Finally, we give two constructions for semiautomorphic inverse property loops based on Chein’s and de Barros and Juriaans’ doubling constructions. 相似文献
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J. A. Erdos 《Integral Equations and Operator Theory》1982,5(1):127-130
It is proved by elementary methods that the strongly closed algebra generated by the Volterra operator V is the commutant of V. 相似文献
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《Journal of Functional Analysis》1987,71(1):47-68
This paper investigates the strong commutant, the weak commutant and the form commutant of an unbounded symmetric (nonself-adjoint) operator and of an unbounded 1-representation on a Hilbert space. For two examples of unbounded symmetric operators these commutants are described in terms of singular integral operators and of Toeplitz operators, respectively. 相似文献
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Dmitri I. Panyushev 《Bulletin des Sciences Mathématiques》2004,128(10):859-870
Let g be a simple Lie algebra. An element x∈g is said to be reachable, if it is contained in the commutant of its centraliser. Any reachable element is necessarily nilpotent. We study various properties of reachable elements, and a relationship between the property of being reachable and the codimension of the boundary of the corresponding orbit. Some general estimates for the boundary of an arbitrary nilpotent orbit is given. 相似文献
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Two operations on sets of bounded operators on Hilbert space are studied: One produces Jordan algebras and the other, its inverse in a certain sense, produces self-adjoint linear spaces. The question of which Jordan algebras arise from the first of these operations is investigated. It is shown that, in many cases, R has this property if and only if the complex associative algebra R + iR is equal to its double commutant. Thus, a by-product of the study is another approach to double commutant theorems. 相似文献