English
Related papers

Related papers: Hochschild Cohomological Dimension is Not Upper Se…

200 papers

We introduce an equivariant version of Hochschild cohomology as the deformation cohomology to study equivariant deformations of associative algebras equipped with finite group actions.

Rings and Algebras · Mathematics 2018-04-17 Goutam Mukherjee , Raj Bhawan Yadav

We show that semiprojectivity of a C*-algebra is preserved when passing to C*-subalgebras of finite codimension. In particular, any pullback of two semiprojective C*-algebras over a finite-dimensional C*-algebra is again semiprojective.

Operator Algebras · Mathematics 2014-05-13 Dominic Enders

The (co)homological dimension of homomorphism $\phi:G\to H$ is the maximal number $k$ such that the induced homomorphism is nonzero for some $H$-module. The following theorems are proven: THEOREM 1. For every homomorphism $\phi:G\to H$ of a…

Algebraic Topology · Mathematics 2023-02-28 Aditya De Saha , Alexander Dranishnikov

It is proved that the associative differential graded algebra of (polynomial) polyvector fields on a vector space (may be infinite- dimensional) is quasi-isomorphic to the corresponding cohomological Hochschild complex of (polynomial)…

Quantum Algebra · Mathematics 2007-05-23 Boris Shoikhet

In this paper we define a new cohomology for multiplicative Hom-associative algebras, which generalize Hochschild cohomology and fits with deformations of Hom-associative algebras including the structure map $\alpha$. It is a generalization…

Rings and Algebras · Mathematics 2018-06-05 Benedikt Hurle , Abdenacer Makhlouf

We prove that Hochschild cohomology of a certain class of fully group-graded algebras is a Mackey functor. We use the machinery of transfer maps between the Hochschild cohomology of symmetric algebras.

Rings and Algebras · Mathematics 2014-10-17 Tiberiu Coconet , Constantin-Cosmin Todea

In this paper, we study the second adjoint cohomology of the compexification of the real conformal Galilei algebras \(\mathfrak{cga}_\ell(d,\mathbb{R})\) and their central extensions. These algebras are non-semisimple Lie algebras that…

Rings and Algebras · Mathematics 2025-08-26 Abror Khudoyberdiyev , Doston Jumaniyozov

We extend the notion of monogenic extension to the noncommutative setting, and we study the Hochschild cohomology ring of such an extension. As an aplication we complete the computation of the cohomology ring of the rank one Hopf algebras…

K-Theory and Homology · Mathematics 2007-06-13 Marco Farinati , Jorge A. Guccione , Juan J. Guccione

We obtain a decomposition for the Hochschild cochain complex of a split algebra and we study some properties of the cohomology of each term of this decomposition. Then, we consider the case of trivial extensions, specially of Frobenius…

K-Theory and Homology · Mathematics 2007-05-23 Jorge A. Guccione , Juan J. Guccione

In Rufus Willett's and the authors paper "Bounded Derivations on Uniform Roe Algebras" we showed that all bounded derivations on a uniform Roe algebra $C^*_u(X)$ associated to a bounded geometry metric space $X$ are inner. This naturally…

Operator Algebras · Mathematics 2021-09-29 Matthew Lorentz

Let $L$ be a finite dimensional Lie $F$-algebra endowed with a generalized action by an associative algebra $H$. We investigate the exponential growth rate of the sequence of $H$-graded codimensions $c_n^H(L)$ of $L$ which is a measure for…

Rings and Algebras · Mathematics 2020-03-26 Geoffrey Janssens

This paper explores the structure of low-dimensional cohomology groups in the context of complex nilpotent associative algebras. Specifically, we study 5-dimensional complex nilpotent associative algebras satisfying $\mathcal{A}^4 = 0$ and…

Rings and Algebras · Mathematics 2025-12-11 Bouzid Mosbahi , Imed Basdouri , Jean Lerbet

This is a further investigation of our approach to group actions in homological algebra in the settings of homology of {\Gamma}-simplicial groups, particularly of {\Gamma}-equivariant homology and cohomology of {\Gamma}-groups. This…

K-Theory and Homology · Mathematics 2021-07-26 Hvedri Inassaridze

The Gerstenhaber and Schack cohomology comparison theorem asserts that there is a cochain equivalence between the Hochschild complex of a certain algebra and the usual singular cochain complex of a space. We show that this comparison…

Quantum Algebra · Mathematics 2016-09-07 F. Patras

The main objective of this paper is to provide a theory for computing the Hochschild cohomology of algebras arising from a linear category with finitely many objects and zero compositions. For this purpose, we consider such a category using…

Rings and Algebras · Mathematics 2018-08-02 Cibils Claude , Lanzilotta Marcelo , Marcos N. Eduardo , Solotar Andrea

The associator of a non-associative algebra is the curvature of the Hochschild quasi-complex. The relationship ``curvature-associator'' is investigated. Based on this generic example, we extend the geometric language of vector fields to a…

Differential Geometry · Mathematics 2007-05-23 Lucian M. Ionescu

The main goal of this paper is to investigate the structure of Hopf algebras with the property that either its Jacobson radical is a Hopf ideal or its coradical is a subalgebra. In order to do that we define the Hochschild cohomology of an…

Quantum Algebra · Mathematics 2009-09-29 A. Ardizzoni , C. Menini , D. Stefan

We provide a formula for the change of the dimension of the first Hoch\-schild cohomology vector space of bound quiver algebras when adding new arrows. For this purpose we show that there exists a short exact sequence which relates the…

K-Theory and Homology · Mathematics 2019-08-15 Claude Cibils , Marcelo Lanzilotta , Eduardo N. Marcos , Sibylle Schroll , Andrea Solotar

We interpret Hochschild cohomology as the Lie algebra of the derived Picard group (in the sense of Rouquier-Zimmermann and Yekutieli) and deduce that it is preserved under derived equivalences.

K-Theory and Homology · Mathematics 2007-05-23 Bernhard Keller

We define Hochschild cohomology of the second kind for differential graded (dg) or curved algebras as a derived functor in the twisted derived category, and show that it is invariant under suitable Morita equivalences of the second kind. A…

Category Theory · Mathematics 2026-02-20 Ai Guan , Julian Holstein , Andrey Lazarev