共查询到20条相似文献,搜索用时 15 毫秒
1.
Koji Fujiwara 《Transactions of the American Mathematical Society》2000,352(3):1113-1129
We study the second bounded cohomology of an amalgamated free product of groups, and an HNN extension of a group. As an application, we show that a group with infinitely many ends has infinite dimensional second bounded cohomology.
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We extend Connes's computation of the cyclic cohomology groups of smooth algebras arising from foliations with separated graphs. We find that the characteristic classes of foliations factor through these groups. Our results also explain some results of Atiyah and Segal on orbifold Euler characteristic in the setting of cyclic homology.Partially supported by NSF grants DMS 92-03517 and DMS 89-03248.Partially supported by NSF grant DMS 92-05548. 相似文献
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The authors prove that all n-th completely bounded cohomology groups of a nest algebra T(N) acting on a separable Hilbert space are trivial when the coefficients lie in any ultraweakly closed T(N)-bimodule containing the nest algebra. They also prove that Hcbn(A, M)(?)Hcbn(A, A) for all n≥1 and a CSL algebra A with an ultraweakly closed A-bimodule M containing A. 相似文献
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Let be a unital Banach algebra. A projection in which is equivalent to the identitity may give rise to a matrix-like structure on any two-sided ideal in . In this set-up we prove a theorem to the effect that the bounded cohomology vanishes for all . The hypotheses of this theorem involve (i) strong H-unitality of , (ii) a growth condition on diagonal matrices in , and (iii) an extension of in by an amenable Banach algebra. As a corollary we show that if is an infinite dimensional Banach space with the bounded approximation property, is an infinite dimensional -space, and is the Banach algebra of approximable operators on , then for all .
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A. Blanco 《Journal of Functional Analysis》2011,261(1):111-148
We investigate the simplicial cohomology of certain Banach operator algebras. The two main examples considered are the Banach algebra of all bounded operators on a Banach space and its ideal of approximable operators. Sufficient conditions will be given forcing Banach algebras of this kind to be simplicially trivial. 相似文献
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John Roe 《K-Theory》1990,4(6):501-512
A geometric version of the Novikov conjecture states that certain cohomology classes of a complete metric space arise from an ideal boundary. We prove this for spaces hyperbolic in the sense of Gromov. 相似文献
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Marc Chardin Kamran Divaani-Aazar 《Proceedings of the American Mathematical Society》2008,136(8):2749-2754
We prove a duality theorem for graded algebras over a field that implies several known duality results: graded local duality, versions of Serre duality for local cohomology and of Suzuki duality for generalized local cohomology, and Herzog-Rahimi bigraded duality.
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In this article, we prove a comparison theorem between the Dwork cohomology introduced by Adolphson and Sperber and the rigid cohomology. As a corollary, we can calculate the rigid cohomology of Dwork isocrystal on torus. 相似文献
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Tariel Kiguradze V. Lakshmikantham 《Journal of Mathematical Analysis and Applications》2006,324(2):1242-1261
For the nonlinear hyperbolic equation
u(2,1)=f(x,t,u,u(1,0),u(2,0),u(0,1),u(1,1)) 相似文献
11.
Ling JIA & Fang LI Department of Mathematics Ludong University Yantai China Department of Mathematics Zhejiang University Hangzhou China 《中国科学A辑(英文版)》2007,50(5):665-674
In this paper, we reveal that a weak entwining structure admits a rich cohomology theory. As an application we compute the cohomology of a weak entwining structure associated to a weak coalgebra-Galois extension. 相似文献
12.
R. Huber 《Compositio Mathematica》1998,112(2):217-235
We show that, for certain types of rigid analytic varieties X and constructible l-adic sheaves (Fn)n on, one has
. As an application we obtain that, for an algebraic variety X and associated rigid analytic variety Xrig, the l-adic cohomology of X and Xrig agree. 相似文献
13.
Ethan Berkove 《Transactions of the American Mathematical Society》2006,358(3):1033-1049
We calculate the integral cohomology ring structure for various members of the Bianchi group family. The main tools we use are the Bockstein spectral sequence and a long exact sequence derived from Bass-Serre theory.
14.
Michael Hellus Jü rgen Stü ckrad 《Proceedings of the American Mathematical Society》2008,136(2):489-498
In the first section of this paper we present generalizations of known results on the set of associated primes of Matlis duals of local cohomology modules; we prove these generalizations by using a new technique. In section 2 we compute the set of associated primes of the Matlis dual of , where is a -dimensional local ring and an ideal such that and .
15.
The Hochschild cohomology of the quasi-entwining structure 总被引:1,自引:0,他引:1
LI Hui & YAO HaiLou College of Applied Science Beijing University of Technology Beijing China 《中国科学 数学(英文版)》2010,(4)
We give a concept of quasi-entwining structure,and investigate the Hochschild cohomology of the quasi-entwining structure.We obtain the equivalent theorems on the Hochschild cohomology of the quasientwining structure.In particular,we get the isomorphism theorem between the Hochschild cohomology of coalgebra structures and the Hochschild cohomology of the dual algebra structures for the quasi-entwining structures of finite-dimensional algebras and coalgebras. 相似文献
16.
In this paper we prove some properties of the nonabelian cohomology of a group with coefficients in a connected Lie group . When is finite, we show that for every -submodule of which is a maximal compact subgroup of , the canonical map is bijective. In this case we also show that is always finite. When and is compact, we show that for every maximal torus of the identity component of the group of invariants , is surjective if and only if the -action on is -semisimple, which is also equivalent to the fact that all fibers of are finite. When , we show that is always surjective, where is a maximal compact torus of the identity component of . When is cyclic, we also interpret some properties of in terms of twisted conjugate actions of .
17.
We determine the Hochschild cohomology algebras of the square-free monomial complete intersections. In particular we provide an explicit formula for the cup product which gives the cohomology module an algebra structure and then we describe this structure in terms of generators and relations. In addition, we compute the Hilbert series of the Hochschild cohomology of these algebras. 相似文献
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Yusuf Civan 《Proceedings of the American Mathematical Society》2006,134(5):1537-1548
We study the enumeration problem of stably complex structures on bounded flag manifolds arising from omniorientations, and determine those induced by almost complex structures. We also enumerate the stably complex structures on these manifolds which bound, therefore representing zero in the complex cobordism ring .