English
Related papers

Related papers: A theory of algebraic cocycles

200 papers

An operad describes a category of algebras and a (co)homology theory for these algebras may be formulated using the homological algebra of operads. A morphism of operads $f:\mathcal{O}\rightarrow\mathcal{P}$ describes a functor allowing a…

Rings and Algebras · Mathematics 2014-03-20 James Griffin

We study the cup product on the Hochschild cohomology of the stack quotient [X/G] of a smooth quasi-projective variety X by a finite group G. More specifically, we construct a G-equivariant sheaf of graded algebras on X whose G-invariant…

Algebraic Geometry · Mathematics 2018-12-13 Cris Negron , Travis Schedler , Pieter Belmans , Pavel Etingof

We define the Hochschild (co)homology of a ringed space relative to a locally free Lie algebroid. Our definitions mimic those of Swan and Caldararu for an algebraic variety. We show that our (co)homology groups can be computed using…

Algebraic Geometry · Mathematics 2011-03-29 Damien Calaque , Carlo A. Rossi , Michel Van den Bergh

We study the multiplicative structure of orbifold Hochschild cohomology in an attempt to generalize the results of Kontsevich and Calaque-Van den Bergh relating the Hochschild and polyvector field cohomology rings of a smooth variety. We…

Algebraic Geometry · Mathematics 2021-01-19 Andrei Caldararu , Shengyuan Huang

This paper explores the cup and cap products within the cohomology and homology groups of ample groupoids, focusing on their applications and fundamental properties. Ample groupoids, which are \'etale groupoids with a totally disconnected…

Operator Algebras · Mathematics 2025-06-25 Hiroki Matui , Takehiko Mori

We define abelian extensions of algebras in congruence-modular varieties. The theory is sufficiently general that it includes, in a natural way, extensions of R-modules for a ring R. We also define a cohomology theory, which we call clone…

Rings and Algebras · Mathematics 2007-05-23 William H. Rowan

For any type of fundamental groupoid scheme, we construct an algebraic cohomology theory for varieties with coefficients in the base field. This is a minor variant of \'etale cohomology, involving neither de Rham complexes nor…

Algebraic Geometry · Mathematics 2026-02-16 Hyuk Jun Kweon

We dualise the classical fact that an operad with multiplication leads to cohomology groups which form a Gerstenhaber algebra to the context of cooperads: as a result, a cooperad with comultiplication induces a homology theory that is…

Algebraic Topology · Mathematics 2024-06-12 Niels Kowalzig , Francesca Pratali

We define inductively a sequence of purely algebraic invariants - namely, classes in the Quillen cohomology of the Pi-algebra \pi_* X - for distinguishing between different homotopy types of spaces. Another sequence of such cohomology…

Algebraic Topology · Mathematics 2009-10-31 David Blanc

We present an elementary and self-contained construction of $A_\infty$-algebras, $A_\infty$-bimodules and their Hochschild homology and cohomology groups. In addition, we discuss the cup product in Hochschild cohomology and the spectral…

Rings and Algebras · Mathematics 2016-01-26 Stephan Mescher

We define several versions of the cohomology ring of an associative algebra. These ring structures unify some well known operations from homological algebra and differential geometry. They have some formal resemblance with the quantum…

Quantum Algebra · Mathematics 2007-05-23 Pyszard Nest , Boris Tsygan

In Homotopy Type Theory, cohomology theories are studied synthetically using higher inductive types and univalence. This paper extends previous developments by providing the first fully mechanized definition of cohomology rings. These rings…

Algebraic Topology · Mathematics 2022-12-09 Thomas Lamiaux , Axel Ljungström , Anders Mörtberg

We connect the homotopy type of simplicial moduli spaces of algebraic structures to the cohomology of their deformation complexes. Then we prove that under several assumptions, mapping spaces of algebras over a monad in an appropriate…

Algebraic Topology · Mathematics 2015-07-20 Sinan Yalin

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

We construct a cohomology theory using quasi-smooth derived schemes as generators and an analogue of the bordism relation using derived fibre products as relations. This theory has pull-backs along all morphisms between smooth schemes…

Algebraic Geometry · Mathematics 2019-02-20 Parker Lowrey , Timo Schürg

We study cohomology theories of strongly homotopy algebras, namely $A_\infty, C_\infty$ and $L_\infty$-algebras and establish the Hodge decomposition of Hochschild and cyclic cohomology of $C_\infty$-algebras thus generalising previous work…

Quantum Algebra · Mathematics 2007-05-23 Alastair Hamilton , Andrey Lazarev

We provide and study an equivariant theory of group (co)homology of a group G with coefficients in a gamma-equivariant G-module A, when a separate group "gamma" acts on G and A, generalizing the classical Eilenberg-MacLane (co)homology of…

K-Theory and Homology · Mathematics 2007-05-23 H. Inassaridze

In \cite{baker-ozel}, by using Fredholm index we developed a version of Quillen's geometric cobordism theory for infinite dimensional Hilbert manifolds. This cobordism theory has a graded group structure under topological union operation…

Algebraic Topology · Mathematics 2007-05-23 cenap ozel

We show that the notions of homotopy epimorphism and homological epimorphism in the category of differential graded algebras are equivalent. As an application we obtain a characterization of acyclic maps of topological spaces in terms of…

Algebraic Topology · Mathematics 2021-06-15 Joe Chuang , Andrey Lazarev

A cohomology theory of the adjoint of Hopf algebras, via deformations, is presented by means of diagrammatic techniques. Explicit calculations are provided in the cases of group algebras, function algebras on groups, and the bosonization of…

Quantum Algebra · Mathematics 2007-05-23 J. Scott Carter , Alissa S. Crans , Mohamed Elhamdadi , Masahico Saito