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We compute the cohomology ring of a generalised type of configuration space of points in $\mathbb{R}^r$. This configuration space is indexed by a graph. In the case the graph is complete the result is known and it is due to Arnold and…

Algebraic Topology · Mathematics 2020-04-20 Marcel Bökstedt , Erica Minuz

A Hom-group G is a nonassociative version of a group where associativity, invertibility, and unitality are twisted by a map \alpha: G\longrightarrow G. Introducing the Hom-group algebra KG, we observe that Hom-groups are providing examples…

Group Theory · Mathematics 2018-03-28 Mohammad Hassanzadeh

This paper describes an approach to computer aided calculations in the cohomology of arithmetic groups. It complements existing literature on the topic by emphasizing homotopies and perturbation techniques, rather than cellular subdivision,…

Number Theory · Mathematics 2025-08-26 Graham Ellis

Lecture notes. Introduction to the cohomology of algebras, Lie algebras, Lie bialgebras and quantum groups. Contains a new derivation of the classification of classical r-matrices in terms of deformation cohomology, and a calculation of the…

q-alg · Mathematics 2014-05-27 Christian Fronsdal

We compute bifunctors cohomology for matrix polynomials under conjugation and detect candidates for universal classes in higher invariant theory.

K-Theory and Homology · Mathematics 2016-08-14 Antoine Touzé

We define and discuss G-formality for certain spaces endowed with an action by a compact Lie group. This concept is essentially formality of the Borel construction of the space in a category of commutative differential graded algebras over…

Algebraic Topology · Mathematics 2007-05-23 Steven Lillywhite

We study partial homology and cohomology from ring theoretic point of view via the partial group algebra $\mathbb{K}_{par}G$. In particular, we link the partial homology and cohomology of a group $G$ with coefficients in an irreducible…

Group Theory · Mathematics 2023-11-10 Marcelo Muniz Alves , Mikhailo Dokuchaev , Dessislava H. Kochloukova

The purpose of this article is to show how one might compute the \'etale cohomology groups $H^p_{\acute{e}t}(X,G_m)$ in degrees $p=0$, $1$ and $2$ of a toric variety $X$ with coefficients in the sheaf of units. The method is to reduce the…

alg-geom · Mathematics 2008-02-03 Timothy J. Ford

In this note we give a generalization for the higher order Hochschild cohomology and show that the secondary Hochschild cohomology is a particular case of this new construction.

Rings and Algebras · Mathematics 2016-07-26 Bruce R. Corrigan-Salter , Mihai D. Staic

We describe a graded extension of the usual Hecke algebra: it acts in a graded fashion on the cohomology of an arithmetic group $\Gamma$. Under favorable conditions, the cohomology is freely generated in a single degree over this graded…

Number Theory · Mathematics 2020-02-19 Akshay Venkatesh

We prove the existence of a sequence of commutative diagrams generalizing existing results on the cohomology of the Borel-Serre boundary and well-rounded retract to the context of the well-tempered complex. Our main theorem provides a…

Number Theory · Mathematics 2025-10-21 Dylan Galt , Mark McConnell

We give algorithms for the computation of the algebraic de Rham cohomology of open and closed algebraic sets inside projective space or other smooth complex toric varieties. The methods, which are based on Gr\"obner basis computations in…

Algebraic Geometry · Mathematics 2009-09-25 Uli Walther

In group representations several inductions given by tensoring with appropriate bimodules may be reconstructed via homology of $G$-posets with $G$-equivariant coefficients. For this purpose, we need various local categories of a finite…

Representation Theory · Mathematics 2018-10-23 Fei Xu

We compute the Hochschild cohomology groups of the cluster-tilted algebras of finite representation type.

Representation Theory · Mathematics 2012-05-04 Sefi Ladkani

We present an algorithm to compute the Hecke operators on the equivariant cohomology of an arithmetic subgroup $\Gamma$ of the general linear group $\mathrm{GL}_n$. This includes $\mathrm{GL}_n$ over a number field or a finite-dimensional…

Number Theory · Mathematics 2020-12-08 Mark McConnell , Robert MacPherson

The codomain category of a generalized homology theory is the category of modules over a ring. For an abelian category A, an A-valued (generalized) homology theory is defined by formally replacing the category of modules with the category…

Algebraic Topology · Mathematics 2020-05-12 Minkyu Kim

Given an arrangement of subtori of arbitrary codimension in a torus, we compute the cohomology groups of the complement. Then, using the Leray spectral sequence, we describe the multiplicative structure on the graded cohomology. We also…

Algebraic Topology · Mathematics 2023-03-08 Luca Moci , Roberto Pagaria

Recent work of Chen He has determined through GKM methods the Borel equivariant cohomology with rational coefficients of the isotropy action on a real Grassmannian and an real oriented Grassmannian through GKM methods. In this expository…

Algebraic Topology · Mathematics 2023-11-28 Jeffrey D. Carlson

Higher derivations on an associative algebra generalizes higher order derivatives. We call a tuple consisting of an algebra and a higher derivation on it by an AssHDer pair. We define a cohomology for AssHDer pairs with coefficients in a…

Rings and Algebras · Mathematics 2020-03-20 Apurba Das

We study the homology groups of the complement of a complexified real line arrangement with coefficients in complex rank-one local systems. Using Borel--Moore homology, we establish an algorithm computing their dimensions via the real…

Algebraic Geometry · Mathematics 2026-04-29 Baiting Xie , Chenglong Yu