共查询到20条相似文献,搜索用时 15 毫秒
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Gary F. Birkenmeier 《代数通讯》2013,41(12):5134-5151
In this paper the idea of an intrinsic extension of a ring, first proposed by Faith and Utumi, is generalized and studied in its own right. For these types of ring extensions, it is shown that, with relatively mild conditions on the base ring, R, a complete set of primitive idempotents (a complete set of left triangulating idempotents, a complete set of centrally primitive idempotents) can be constructed for an intrinsic extension, T, from a corresponding set in the base ring R. Examples and applications are given for rings that occur in functional analysis and group ring theory. 相似文献
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本文证明了在正规locale范畴中,Banaschewski-Mulvey形式的紧正则反射与Johnstone形式的Wallman紧化一致,从而推广了Johnstone在文献[4]中的主要结果. 相似文献
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51.IntroductionandPreIiminariesThemonoidofendomorphismsofagraph,inparticular,thatofstrongendomorphismsofagraph,hasbeentheobjectofresearchesinthetheoryofsemigroupsforquitesometime(cf.Llj-Lloj).LlJandL2jcanserveasasurvey.Theaimoftheseresearchesistocon-tributetothealgebraicanalysisofgraphs.Thesubjectyieldssomeinterestsincetheresultsoftheseresearchesmayopenvastpossibilitiesforapplicationsofsemigrouptheorytographtheo-ry.InL1]andL3j,ithasbeenprovedthatforfinitegraphG,sEnd(G),themonoidofstrongen… 相似文献
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This paper answers negatively the question of whether the sets of idempotents in the weakly almost periodic compactifications of and are closed.
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Matej Brešar 《代数通讯》2013,41(1):154-163
Let 𝒜 be a ring, let ? be an 𝒜-bimodule, and let 𝒞 be the center of ?. A map F:𝒜 → ? is said to be range-inclusive if [F(x), 𝒜] ? [x, ?] for every x ∈ 𝒜. We show that if 𝒜 contains idempotents satisfying certain technical conditions (which we call wide idempotents), then every range-inclusive additive map F:𝒜 → ? is of the form F(x) = λx + μ(x) for some λ ∈ 𝒞 and μ:𝒜 → 𝒞. As a corollary we show that if 𝒜 is a prime ring containing an idempotent different from 0 and 1, then every range-inclusive additive map from 𝒜 into itself is commuting (i.e., [F(x), x] = 0 for every x ∈ 𝒜). 相似文献
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Themonoidofendomorphismsofagraph ,inparticular,thatofstrongendomorphismsofagraph ,hasbeentheobjectofresearchesinthetheoryofsemigroupsforquitesometime(cf .[1 ]— [9]) .Asispointedoutinsomestandardbooksonsemigrouptheorysuchas[1 0 ],theideaofdeducingfactsaboutthesemi… 相似文献
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Peter J.C. Dickinson 《Journal of Mathematical Analysis and Applications》2011,380(1):377-395
The copositive cone, and its dual the completely positive cone, have useful applications in optimisation, however telling if a general matrix is in the copositive cone is a co-NP-complete problem. In this paper we analyse some of the geometry of these cones. We discuss a way of representing all the maximal faces of the copositive cone along with a simple equation for the dimension of each one. In doing this we show that the copositive cone has faces which are isomorphic to positive semidefinite cones. We also look at some maximal faces of the completely positive cone and find their dimensions. Additionally we consider extreme rays of the copositive and completely positive cones and show that every extreme ray of the completely positive cone is also an exposed ray, but the copositive cone has extreme rays which are not exposed rays. 相似文献
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在最小Q-过程中断条件下证明了Martin流出边界与Ray-Knight紧化之间存在一定的映射关系.并举例说明如果最小Q-过程中断且无限流出,则Ray-Knight紧化可能比Martin流出边界要多出一些点.因此在Markov链的构造论中不能只考虑Martin边界. 相似文献
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Reinhard Börger 《Applied Categorical Structures》2007,15(5-6):493-497
We show that the poset of symmetric idempotents of a (non-commutative) unital ring with involution in the obvious order need
not admit finite joins and meets.
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John David Herron 《Integral Equations and Operator Theory》2009,64(2):193-201
We show that the spectral radius algebras of certain quadratic operators possess nontrivial invariant subspaces. Additionally,
such algebras properly contain the operator’s commutant, so that the invariant subspaces are in some sense beyond hyperinvariant.
The spectral radius algebras of idempotents are completely described and, as a consequence, it is shown that every intransitive
collection of operators must be contained in a norm-closed proper spectral radius algebra.
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Romain Gicquaud 《偏微分方程通讯》2013,38(8):1313-1367
In this paper we pursue the work initiated in [6, 7]: study the extent to which conformally compact asymptotically hyperbolic metrics can be characterized intrinsically. We show how the decay rate of the sectional curvature to ?1 controls the Hölder regularity of the compactified metric. To this end, we construct harmonic coordinates that satisfy some Neumann-type condition at infinity. Combined with a new integration argument, this permits us to recover to a large extent our previous result without any decay assumption on the covariant derivatives of the Riemann tensor. 相似文献
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This paper incorporates cones on virtual multipliers of inputs and outputs into DEA analysis. Cone DEA models are developed
to generalize the dual of the BCC models as well as congestion models. Input-output data and/or numbers of DMUs for BCC models
are inadequate to capture many aspects where judgments, expert opinions, and other external information should be taken into
analysis. Cone DEA models, on the other hand, offer improved definitions of efficiency over general cone and polyhedral cone
structures. The relationships between cone models and BCC models as well as those between cone models and congestion models
are discussed in the development. Two numerical examples are provided to illustrate our findings. 相似文献
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Huang and Zhang reviewed cone metric spaces in 2007 [Huang Long-Guang, Zhang Xian, Cone metric spaces and fixed point theorems of contractive mappings, J. Math. Anal. Appl. 332 (2007) 1468-1476]. We shall prove that there are no normal cones with normal constant M<1 and for each k>1 there are cones with normal constant M>k. Also, by providing non-normal cones and omitting the assumption of normality in some results of [Huang Long-Guang, Zhang Xian, Cone metric spaces and fixed point theorems of contractive mappings, J. Math. Anal. Appl. 332 (2007) 1468-1476], we obtain generalizations of the results. 相似文献
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Approximate nondominated solutions of real vector optimization problems are characterized using the concept of translated
cones. Relationships between these solutions and Pareto nondominated points are examined, and the problem of optimizing over
the set of approximate solutions is addressed.
This research was supported by the National Science Foundation, Grant DMS-0425768, and by the Automotive Research Center,
a US Army TACOM Center of Excellence for Modeling and Simulation of Ground Vehicles at the University of Michigan 相似文献
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Yu. E. Linke 《Mathematical Notes》2005,77(5-6):817-830
We prove that the cone of bounded lower semicontinuous functions defined on a Tychonoff space X is algebraically and structurally isomorphic and isometric to a convex cone contained in the cone of all bounded lower semicontinuous functions defined on the Stone-Cech compactification βX if and only if the space X is normal. We apply this theorem to the study of relationship between a class of multivalued maps and sublinear operators. Using these results, we obtain new proofs of theorems about continuous selections.__________Translated from Matematicheskie Zametki, vol. 77, no. 6, 2005, pp. 886–902.Original Russian Text Copyright ©2005 by Yu. E. Linke. 相似文献
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We describe the extension of the multiplication on a not-necessarily-discrete topological monoid to its flow compactification. We offer two applications. The first is a nondiscrete version of Hindman's Theorem, and the second is a characterization of the projective minimal and elementary flows in terms of idempotents of the flow compactification of the monoid. 相似文献