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71.
The Isomorphism Conjecture is a conceptional approach towards a calculation of the algebraic K-theory of a group ring RΓ, where Γ is an infinite group. In this paper we prove the conjecture in dimensions n<2 for fundamental groups of closed Riemannian manifolds with strictly negative sectional curvature and arbitrary coefficient rings R. If R is regular this leads to a concrete calculation of low dimensional K-theory groups of RΓ in terms of the K-theory of R and the homology of the group. 相似文献
72.
Shang Yuan LIN Bin XIN 《数学学报(英文版)》2005,21(6):1521-1524
In this paper, we present some modules over the rank-three quantized Weyl algebra, which are closely related to modules over some vertex algebras. The isomorphism classes among these modules are also determined. 相似文献
73.
量子环面上一类导子李代数的结构和自同构群 总被引:2,自引:0,他引:2
本文研究量子环面上的一类导子李代数,它包含了Virasoro-Like代数及其q类似.首先证明了这 类导子李代数之间的同构一定是分次同构,并进一步给出了代数同构的充要条件及同构映射的具体表达 式,最后确定了该类李代数的自同构群. 相似文献
74.
Rodolfo De Sapio 《Topology and its Applications》2003,130(3):221-237
Let πi :Ei→M, i=1,2, be oriented, smooth vector bundles of rank k over a closed, oriented n-manifold with zero sections si :M→Ei. Suppose that U is an open neighborhood of s1(M) in E1 and F :U→E2 a smooth embedding so that π2Fs1 :M→M is homotopic to a diffeomorphism f. We show that if k>[(n+1)/2]+1 then E1 and the induced bundle f*E2 are isomorphic as oriented bundles provided that f have degree +1; the same conclusion holds if f has degree −1 except in the case where k is even and one of the bundles does not have a nowhere-zero cross-section. For n≡0(4) and [(n+1)/2]+1<kn we give examples of nonisomorphic oriented bundles E1 and E2 of rank k over a homotopy n-sphere with total spaces diffeomorphic with orientation preserved, but such that E1 and f*E2 are not isomorphic oriented bundles. We obtain similar results and counterexamples in the more difficult limiting case where k=[(n+1)/2]+1 and M is a homotopy n-sphere. 相似文献
75.
给出Fuzzy粗糙半群与Fuzzy粗糙同态的定义,并讨论Fuzzy粗糙半群的Fuzzy粗糙同态与Fuzzy粗糙商半群的Fuzzy粗糙同构。 相似文献
76.
Let ? be a zero-product preserving bijective bounded linear map from a unital algebra A onto a unital algebra B such that ?(1)=k. We show that if A is a CSL algebra on a Hilbert space or a J-lattice algebra on a Banach space then there exists an isomorphism ψ from A onto B such that ?=kψ. For a nest algebra A in a factor von Neumann algebra, we characterize the linear maps on A such that δ(x)y+xδ(y)=0 for all x,y∈A with xy=0. 相似文献
77.
78.
We give the number and representatives of isomorphism classes of hyperelliptic curves of genus g defined over finite fields
, g=1,2,3. These results have applications to hyperelliptic curve cryptography. 相似文献
79.
直觉模糊集的扩张运算 总被引:23,自引:2,他引:21
在 K.Atanassov引进直觉模糊集概念的基础上 ,首先给出乘积的定义和扩张原理 ,并讨论群上的直觉模糊集的并、交等扩张运算 ;其次在两个经典群同态、同构的条件下 ,研究直觉模糊集乘积的扩张运算问题。 相似文献
80.
The power graph of a group is the graph whose vertex set is the group, two elements being adjacent if one is a power of the other. We observe that non-isomorphic finite groups may have isomorphic power graphs, but that finite abelian groups with isomorphic power graphs must be isomorphic. We conjecture that two finite groups with isomorphic power graphs have the same number of elements of each order. We also show that the only finite group whose automorphism group is the same as that of its power graph is the Klein group of order 4. 相似文献