(Co)Homology Theories for Oriented Algebras

We study three different (co)homology theories for a family of pullbacks of algebras that we call oriented. We obtain a Mayer Vietoris long exact sequence of Hochschild and cyclic homology and cohomology groups for these algebras. We give examples showing that our sequence for Hochschild cohomology groups is different from the known ones. In case the algebras are given by quiver and relations, and that the simplicial homology and cohomology groups are defined, we obtain a similar result in a slightly wider context. Finally, we also study the fundamental groups of the bound quivers involved in the pullbacks.     

Invariance of Hochschild and Cyclic (Co)homology of Superalgebras Under Graded Equivalences

It is shown that the Hochschild and cyclic (co)homology of superalgebras are graded equivalent invariants.     

Hochschild (Co)homology of Exterior Algebras

The minimal projective bimodule resolutions of the exterior algebras are explicitly constructed. They are applied to calculate the Hochschild (co)homology of the exterior algebras. Thus the cyclic homology of the exterior algebras can be calculated in case the underlying field is of characteristic zero. Moreover, the Hochschild cohomology rings of the exterior algebras are determined by generators and relations.     

On the Hochschild (co)homology of a monomial algebra given by a cyclic quiver and two zero-relations

Let K be an algebraically closed field and Γ a cyclic quiver. Xu and Wang investigated the Hochschild (co)homology groups of KΓ∕I, where I is an ideal of KΓ generated by one path. In this paper, in the case that I is an ideal of KΓ generated by two paths, we give the module structure of the Hochschild (co)homology groups of KΓ∕I.     

Hochschild and cyclic homology of finite type algebras

We study Hochschild and cyclic homology of finite type algebras using abelian stratifications of their primitive ideal spectrum. Hochschild homology turns out to have a quite complicated behavior, but cyclic homology can be related directly to the singular cohomology of the strata. We also briefly discuss some connections with the representation theory of reductive p-adic groups.     

Morita 型稳定等价下的模- 相对Hochschild (上) 同调

Ardizzoni, Brzeziński 和Menini 在研究代数的形式光滑性以及形式光滑双模时利用相对右导出函子引入了模- 相对Hochschild 上同调的概念. 本文利用相对左导出函子相应地给出模- 相对Hochschild 同调的定义, 讨论了在Morita 型稳定等价下, 代数的Hochschild (上) 同调、相对Hochschild (上) 同调以及模- 相对Hochschild (上) 同调三者之间的关系, 证明了模- 相对Hochschild 同调与上同调是Morita 型稳定等价下的不变量. 作为该结果的应用, 我们得到形式光滑双模与可分双模的一种构造方法, 并给出了通常意义下的Hochschild (上) 同调是Morita 型稳定等价不变量的一种新的证明.     

Twisted Hochschild Homology of Quantum Hyperplanes*

The twisted Hochschild homology groups of generic quantum hyperplanes are calculated using the Koszul resolution. For the example of the two-dimensional quantum plane also the twisted cyclic homology groups are determined. *Partially supported by Polish State Committee for Scientific Research (KBN) under grant 2 P03B 022 25     

The first cohomology group of trivial extensions of special biserial algebras

Given a finite dimensional special biserial algebra A with normed basis we obtain the dimension formulae of the first Hochschild homology groups of A and the vector space Alt(DA). As a consequence, an explicit dimension formula of the first Hochschild cohomology group of trivial extension TA = A×DA in terms of the combinatorics of the quiver and relations is determined.     

一个自入射Koszul代数的Hochschild同调与循环同调

代数的Hochschild同调群与其对应的Gabriel箭图的循环圈有着紧密的联系.本文基于Furuya构造的一个四点自入射Koszul代数的极小投射双模分解,用组合的方法计算了该代数的Hochschild同调空间的维数,并用循环圈的语言给出该代数的Hochschild同调空间的一组k-基.进一步,当基础域k的特征为零时,我们也得到了该代数的循环同调群的维数.     

Crossed Product Algebras and the Homology of Certain p-Adic and Adélic Dynamical Systems

We identify the Hochschild, cyclic, and periodic cyclic homology groups of dynamical systems algebras arising from the action of Q on the spaces of finite and infinite adéles of Q. In the process, we establish several results on the homology of the space of functions on a locally compact, totally disconnected space and its crossed products. Then we use these results to compute the homology groups of the Bost–Connes algebra.     

Hochschild and Cyclic Homology of Ore Extensions and Some Examples of Quantum Algebras

For every Ore extension we construct a chain complex giving its Hochschild homology. As an application we compute the Hochschild and cyclic homology of an arbitrary multiparametric affine space and the Hochschild homology of the algebra of differential operators over this space, in the generic case.     

二元外代数的Z_n-Galois覆盖代数的Hochschild(上)同调群

设Λ是特征不整除n的域k上的二元外代数,■是Λ的Zn-Galois覆盖代数.首先构造了■的极小投射双模分解,并由此清晰地计算了■的各阶Hochschild同调和上同调群的维数;并且在域的特征为零时,计算了■的循环同调群的维数.     

Twisted Homology of Quantum SL(2)

We calculate the twisted Hochschild and cyclic homology (in the sense of Kustermans, Murphy and Tuset) of the coordinate algebra of the quantum SL(2) group relative to twisting automorphisms acting by rescaling the standard generators a,b,c,d. We discover a family of automorphisms for which the “twisted” Hochschild dimension coincides with the classical dimension of , thus avoiding the “dimension drop” in Hochschild homology seen for many quantum deformations. Strikingly, the simplest such automorphism is the canonical modular automorphism arising from the Haar functional. In addition, we identify the twisted cyclic cohomology classes corresponding to the three covariant differential calculi over quantum SU(2) discovered by Woronowicz.     

一个Cluster-Tilted代数的Hochschild同调与循环同调

基于Furuya构造的一个Cluster-Tilted代数的极小投射双模分解,用组合的方法计算了Cluster-Tilted代数的Hochschild同调空间的维数与基.当基础域的特征为零时,也计算了代数的循环同调群的维数.     

非单位κ-代数的局部循环同调及切除定理

本文定义了单位过滤k-代数和非单位过滤k-代数的局部Hochschild同调和局部循环同调,给出 了它们之间的局部Connes长正合列．进一步利用循环同调来计算局部循环同调的短正合列公式,讨论 了关于过滤k-代数局部循环同调的切除定理．     

Higher topological cyclic homology and the Segal conjecture for tori

We investigate higher topological cyclic homology as an approach to studying chromatic phenomena in homotopy theory. Higher topological cyclic homology is constructed from the fixed points of a version of topological Hochschild homology based on the n-dimensional torus, and we propose it as a computationally tractable cousin of n-fold iterated algebraic K-theory.The fixed points of toral topological Hochschild homology are related to one another by restriction and Frobenius operators. We introduce two additional families of operators on fixed points, the Verschiebung, indexed on self-isogenies of the n-torus, and the differentials, indexed on n-vectors. We give a detailed analysis of the relations among the restriction, Frobenius, Verschiebung, and differentials, producing a higher analog of the structure Hesselholt and Madsen described for 1-dimensional topological cyclic homology.We calculate two important pieces of higher topological cyclic homology, namely topological restriction homology and topological Frobenius homology, for the sphere spectrum. The latter computation allows us to establish the Segal conjecture for the torus, which is to say to completely compute the cohomotopy type of the classifying space of the torus.     

Homology of algebras of families of pseudodifferential operators

We compute the Hochschild, cyclic, and periodic cyclic homology groups of algebras of families of Laurent complete symbols on manifolds with corners. We show in particular that the spectral sequence associated with Hochschild homology degenerates at E² and converges to Hochschild homology. As a byproduct, we identify the space of residue traces on fibrations by manifolds with corners. In the process, we prove some structural results about algebras of complete symbols on manifolds with corners.     

Hochschild (Co)Homology of Hopf Crossed Products*

For a general crossed product E = A#_f H, of an algebra A by a Hopf algebra H, we obtain complexes smaller than the canonical ones, giving the Hochschild homology and cohomology of E. These complexes are equipped with natural filtrations. The spectral sequences associated to them coincide with the ones obtained using a natural generalization of the direct method introduced in Trans. Amer. Math. Soc. 74 (1953) 110–134. We also get that if the 2-cocycle f takes its values in a separable subalgebra of A, then the Hochschild (co)homology of E with coefficients in M is the (co)homology of H with coefficients in a (co)chain complex.     

Noncommutative homology of some three-dimensional quantum spaces

We compute the Hochschild and cyclic homology of certain three-dimensional quantum spaces (type A algebras), introduced by Artin and Schelter. We show that the Hochschild homology is determined by the quasi-classical limit.