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Let $G$ be the classical group, and let Hom$(\mathbb{Z}^m,G)$ denote the space of commuting $m$-tuples in $G$. Baird proved that the cohomology of Hom$(\mathbb{Z}^m,G)$ is identified with a certain ring of invariants of the Weyl group of…

Algebraic Topology · Mathematics 2020-10-19 Masahiro Takeda

In this article we study cohomology of a group with coefficients in representations on Banach spaces and its stability under deformations. We show that small, metric deformations of the representation preserve vanishing of cohomology. As…

Group Theory · Mathematics 2014-09-03 Uri Bader , Piotr W. Nowak

For g>2 we study the cohomology classes in the closure of a stratum of abelian differentials defined by the boundary strata of codimension one. As an application, we find an explicit stratification of the spin moduli space for an odd spin…

Geometric Topology · Mathematics 2020-11-12 Ursula Hamenstädt

Given a hypersurface $X\subset \mathbb{P}^{N+1}_{\mathbb{C}}$ Dimca gave a proof showing that the cohomologies of X are the same as the projective space in a range determined by the dimension of the singular locus of X. We prove the analog…

Algebraic Geometry · Mathematics 2018-08-20 David Kazhdan , Tomer M. Schlank

The cohomology of the configuration space of n points in R^3 admits a symmetric group action and has been shown to be isomorphic to the regular representation. One way to prove this is by defining an S^1-action whose fixed point set is the…

Combinatorics · Mathematics 2012-05-15 Daniel Moseley

Commutative K-theory, a cohomology theory built from spaces of commuting matrices, has been explored in recent work of Adem, G\'{o}mez, Gritschacher, Lind, and Tillman. In this article, we use unstable methods to construct explicit…

Algebraic Topology · Mathematics 2019-06-04 Daniel A. Ramras , Bernardo Villarreal

We give some basics about homological algebra of difference representations. We consider both the difference-discrete and the difference-rational case. We define the corresponding cohomology theories and show the existence of spectral…

Algebraic Geometry · Mathematics 2018-11-07 Marcin Chalupnik , Piotr Kowalski

We compute the (stable) \'etale cohomology of $\mathrm{Hom}_{n}(C, \mathcal{P}(\vec{\lambda}))$, the moduli stack of degree $n$ morphisms from a smooth projective curve $C$ to the weighted projective stack $\mathcal{P}(\vec{\lambda})$, the…

Algebraic Geometry · Mathematics 2022-07-07 Oishee Banerjee , Jun-Yong Park , Johannes Schmitt

A recent result of ours [GM] shows that all Hopf algebra liftings of a given diagram in the sense of Andruskiewitsch and Schneider are cocycle deformations of each other. Here we develop a "non-abelian" cohomology theory, which gives a…

Rings and Algebras · Mathematics 2009-09-24 L. Grunenfelder

We study the moduli stacks of real vector bundles of fixed rank and degree on a type I real algebraic curve and determine its mod 2 cohomology algebra in terms of characteristic classes.

Algebraic Geometry · Mathematics 2026-05-29 Luca Dal Molin , Frank Neumann

In this paper, we introduce the concept of crossed module for Hom-Leibniz-Rinehart algebras. We study the cohomology and extension theory of Hom-Leibniz-Rinehart algebras. It is proved that there is one-to-one correspondence between…

Rings and Algebras · Mathematics 2022-12-27 Yanhui Bi , Danlu Chen , Tao Zhang

The purpose of this paper is to study global deformations of Hom-Leibniz algebras. We introduce a cohomology for Hom-Leibniz algebras with values in a Hom-module, characterize versal deformations and provide examples.

Rings and Algebras · Mathematics 2013-03-01 Faouzi Ammar , Zeyneb Ejbehi , Abdenacer Makhlouf

In this paper we show that in a stable range the cohomology of the space of regular algebraic sections of a line bundle $\mathscr{L}$on a curve $X$ is isomorphic to the cohomology of the space of regular $C^{\infty}$sections of the same…

Algebraic Geometry · Mathematics 2022-11-16 Ishan Banerjee

This article is a survey on the cohomology of a reductive algebraic group with coefficients in twisted representations. A large part of the paper is devoted to the advances obtained by the theory of strict polynomial functors initiated by…

K-Theory and Homology · Mathematics 2018-10-04 Antoine Touzé

Aim of this paper is to define a new type of cohomology for multiplicative Hom-Leibniz algebras which controls deformations of Hom-Leibniz algebra structure. The cohomology and the associated deformation theory for Hom-Leibniz algebras as…

Rings and Algebras · Mathematics 2020-11-23 Goutam Mukherjee , Ripan Saha

In this paper, we introduce cohomology of n-Hom-Liebniz algebra morphisms and formal deformation theory of n-Hom-Liebniz algebra morphisms .

Rings and Algebras · Mathematics 2022-10-11 R. B. Yadav

We introduce a new cohomology theory for stacks called elliptic Hochschild homology, prove some fundamental properties and compute it in some classes of examples. We then introduce its periodic cyclic version and show that, over the complex…

Algebraic Geometry · Mathematics 2023-09-18 Nicolò Sibilla , Paolo Tomasini

We explain how the approach of Andre and Quillen to defining cohomology and homology as suitable derived functors extends to generalized (co)homology theories, and how this identification may be used to study the relationship between them.…

Algebraic Topology · Mathematics 2008-02-15 David Blanc

A strong version of the quantization conjecture of Guillemin and Sternberg is proved. For a reductive group action on a smooth, compact, polarized variety (X,L), the cohomologies of L over the GIT quotient X // G equal the invariant part of…

Algebraic Geometry · Mathematics 2007-05-23 Constantin Teleman

The purpose of this paper is to study deformation theory of Hom-associative algebra morphisms and Hom-Lie algebra morphisms. We introduce a suitable cohomology and discuss Infinitesimal deformations, equivalent deformations and…

Rings and Algebras · Mathematics 2017-10-23 Anja Arfa , Nizar Ben Fraj , Abdenacer Makhlouf