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941.
《Journal of Pure and Applied Algebra》2021,225(12):106773
Graded-division algebras are building blocks in the theory of finite-dimensional associative algebras graded by a group G. If G is abelian, they can be described, using a loop construction, in terms of central simple graded-division algebras.On the other hand, given a finite abelian group G, any central simple G-graded-division algebra over a field is determined, thanks to a result of Picco and Platzeck, by its class in the (ordinary) Brauer group of and the isomorphism class of a G-Galois extension of .This connection is used to classify the simple G-Galois extensions of in terms of a Galois field extension with Galois group isomorphic to a quotient and an element in the quotient subject to certain conditions. Non-simple G-Galois extensions are induced from simple T-Galois extensions for a subgroup T of G. We also classify finite-dimensional G-graded-division algebras and, as an application, finite G-graded-division rings. 相似文献
942.
In this paper, we study extensions between two finite irreducible conformal modules over the Schrödinger–Virasoro conformal algebra and the extended Schrödinger–Virasoro conformal algebra. Also, we classify all finite nontrivial irreducible conformal modules over the extended Schrödinger–Virasoro conformal algebra. As a byproduct, we obtain a classification of extensions of Heisenberg–Virasoro conformal modules. 相似文献
943.
《Expositiones Mathematicae》2021,39(4):515-539
The Morse–Sard theorem gives conditions under which the set of critical values of a function between Euclidean spaces has Lebesgue measure zero. Over the years the result has been extended and strengthened in various ways. We present a result, along with a simple proof, that subsumes many of these generalizations. We also review methods of constructing examples showing that differentiability hypotheses cannot be weakened, and we construct a complete set of examples for our result. 相似文献
944.
We define the conformity of marginal and conditional models with a joint model within Walley's theory of coherent lower previsions. Loosely speaking, conformity means that the joint can reproduce the marginal and conditional models we started from. By studying conformity with and without additional assumptions of epistemic irrelevance and independence, we establish connections with a number of prominent models in Walley's theory: the marginal extension, the irrelevant natural extension, the independent natural extension and the strong product. 相似文献
945.
The conditions under which a 2-monotone lower prevision can be uniquely updated (in the sense of focusing) to a conditional lower prevision are determined. Then a number of particular cases are investigated: completely monotone lower previsions, for which equivalent conditions in terms of the focal elements of the associated belief function are established; random sets, for which some conditions in terms of the measurable selections can be given; and minitive lower previsions, which are shown to correspond to the particular case of vacuous lower previsions. 相似文献
946.
AbstractWe classify all complex 6-dimensional nilpotent Tortkara algebras.Communicated by Alberto Facchini 相似文献
947.
研究模糊联盟合作对策tau值的计算方法及其性质. 利用多维线性扩展方法定义了模糊联盟合作对策的tau值, 证明了其存在性、唯一性等性质, 并推导出基于多维线性扩展凸模糊联盟合作对策tau值的计算公式. 研究结果发现, 基于多维线性扩展的模糊联盟合作对策tau值是对清晰联盟合作对策tau值的扩展, 而清晰联盟合作对策tau值仅是其特例. 特别地, 对于凸模糊联盟合作对策, 利用其tau值计算公式, 可进一步简化求解过程. 相似文献
948.
n-Hom Lie algebras are twisted by n-Lie algebras by means of twisting maps. n-Hom Lie algebras have close relationships with statistical mechanics and mathematical physics. The paper main concerns structures and representations of n-Hom Lie algebras. The concept of nρ-cocycle for an n-Hom Lie algebra (G, [,… , ], α) related to a G-module (V, ρ, β) is proposed, and a sufficient condition for the existence of the dual representation of an n-Hom Lie algebra is provided. From a G-module (V, ρ, β) and an nρ-cocycle θ, an n-Hom Lie algebra (Tθ(V ), [, … , ]θ, γ) is constructed on the vector space Tθ(V ) = G⊕V, which is called the Tθ-extension of an n-Hom Lie algebra (G, [, … , ], α) by the G-module (V, ρ, β). 相似文献
949.
Yu Shang & Limin Wang 《数学研究通讯:英文版》2013,29(3):218-230
In this paper, we study ∗-simple type $A$ $ω^2$-semigroups in which$\mathcal{D}^∗ =\widetilde{D}$and $\mathcal{D}^∗|_{E_S} = \mathcal{M}_d$ by the generalized Bruck-Reilly extension and obtain its structure
theorem. We also obtain a criterion for isomorphisms of two such semigroups. 相似文献
950.
可拓学在管理领域中的应用研究进展 总被引:3,自引:1,他引:2
管理的过程就是通过开拓创新处理矛盾问题的过程.可拓学就是这样一门学科,它用形式化的模型研究事物拓展的可能性和开拓创新的规律与方法,并用于解决矛盾问题.对可拓学在管理领域中的应用研究进行了回顾,分析了应用研究的特点.提出了可拓学在"冲突管理"、"系统思考"和"复杂系统管理"中应用的前景. 相似文献