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Related papers: E2 formality via obstruction theory

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We develop two approaches to obstruction theory for deformations of derived isomorphism classes of complexes $Z^\bullet$ of modules for a profinite group $G$ over a complete local Noetherian ring $A$ of positive residue characteristic…

Number Theory · Mathematics 2013-09-03 Frauke M. Bleher , Ted Chinburg

We study the cohomology of Lie superalgebras for the full complex of forms: superforms, pseudoforms and integral forms. We use the technique of spectral sequences to abstractly compute the Chevalley-Eilenberg cohomology. We first focus on…

High Energy Physics - Theory · Physics 2021-06-25 C. A. Cremonini , P. A. Grassi

We study the cohomology ring of the configuration space of unordered points in the two dimensional torus. In particular, we compute the mixed Hodge structure on the cohomology, the action of the mapping class group, the structure of the…

Algebraic Topology · Mathematics 2020-12-16 Roberto Pagaria

We survey decades of research identifying the (co)homology of configuration spaces with Lie algebra (co)homology. The different routes to this one proto-theorem offer genuinely different explanations of its truth, and we attempt to convey…

Algebraic Topology · Mathematics 2025-08-21 Ben Knudsen

In the paper, we consider the class of so-called endo-commutative algebras. From the identity imposed to specify this class, one can easily see that the product in this class preserves the square of elements. We give a complete…

Rings and Algebras · Mathematics 2024-07-09 D. Asrorov , U. Bekbaev , I. Rakhimov

We study a special type of $E_\infty$-operads that govern strictly unital $E_\infty$-coalgebras (and algebras) over the ring of integers. Morphisms of coalgebras over such an operad are defined by using universal $E_\infty$-bimodules. Thus…

Algebraic Topology · Mathematics 2014-02-26 Grigory Rybnikov

We develop an obstruction theory for the existence of gauge equivalences in complete differential graded Lie algebras. Specifically, this theory provides a characterization of homotopy equivalences between differential graded algebras…

Algebraic Topology · Mathematics 2025-09-23 Coline Emprin

This paper investigates cohomology and support varieties for Lie superalgebras and restricted Lie superalgebras over a field of characteristic 2. The existence of an underlying ordinary Lie algebra allows us to obtain results that are still…

Representation Theory · Mathematics 2025-08-15 Christopher M. Drupieski , Jonathan R. Kujawa

In this paper, we define a new cohomology theory for multiplicative Hom-pre-Lie algebras which controls deformations of Hom-pre-Lie algebra structure. This new cohomology is a natural one by considering the structure map. We develop…

Rings and Algebras · Mathematics 2023-08-01 Shuangjian Guo , Ripan Saha

The notions of Lie color 2-algebras and 2-term color L-infty-algebras over a group-graded vector space are introduced and studied. It is proved that the category of Lie color 2-algebras and the category of 2-term color L1-algebras are…

Rings and Algebras · Mathematics 2020-07-01 Tao Zhang

Let $\mathcal{E}$ be the class of finite-dimensional algebras isomorphic to endomorphism algebras of silting complexes over hereditary abelian categories. It is proved that the class $\mathcal{E}$ is closed under taking idempotent…

Representation Theory · Mathematics 2026-03-12 Wei Dai , Changjian Fu , Liangang Peng

This paper studies formality of the differential graded algebra $RHom(E,E)$, where $E$ is a semistable sheaf on a K3 surface. The main tool is Kaledin's theorem on formality in families. For a large class of sheaves $E$, this DG algebra is…

Algebraic Geometry · Mathematics 2010-11-23 Ziyu Zhang

G.W. Mackey's celebrated obstruction theory for projective representations of locally compact groups was remarkably generalized by J. M. G. Fell and R. S. Doran to the wide area of saturated Banach *-algebraic bundles. Analogous obstruction…

Rings and Algebras · Mathematics 2025-08-08 Yuval Ginosar

Generalising a previous work of Jiang and Sheng, a cohomology theory for differential Lie algebras of arbitrary weight is introduced. The underlying $L_\infty[1]$-structure on the cochain complex is also determined via a generalised version…

Rings and Algebras · Mathematics 2024-03-28 Weiguo Lyu , Zihao Qi , Jian Yang , Guodong Zhou

Two examples of $\mathrm{Diff}^+S^1$-invariant closed two-forms obtained from forms on jet bundles, which does not admit equivariant moment maps are presented. The corresponding cohomological obstruction is computed and shown to coincide…

Differential Geometry · Mathematics 2009-06-17 Roberto Ferreiro Pérez , Jaime Muñoz Masqué

Lie bialgebra structures on $e(2)$ are classified. For two Lie bialgebra structures which are not coboundaries (i.e. which are not determined by a classical $r$-matrix) we solve the cocycle condition, find the Lie-Poisson brackets and…

q-alg · Mathematics 2009-10-30 Jan Sobczyk

We introduce a new cohomology for Lie algebroids, and prove that it provides a differential graded Lie algebra which ``controls'' deformations of the structure bracket of the algebroid. We also have a closer look at various special cases…

Differential Geometry · Mathematics 2007-05-23 M. Crainic , I. Moerdijk

Let $\Gamma$ be a finite group acting linearly on a vector space $V$. We compute the Lie algebra cohomology of the Lie algebra of $\Gamma$-invariant formal vector fields on $V$. We use this computation to define characteristic classes for…

Representation Theory · Mathematics 2007-05-23 Ilya Shapiro , Xiang Tang

We study closed, connected, spin 4-manifolds up to stabilisation by connected sums with copies of $S^2 \times S^2$. For a fixed fundamental group, there are primary, secondary and tertiary obstructions, which together with the signature…

Geometric Topology · Mathematics 2024-06-07 Daniel Kasprowski , Mark Powell , Peter Teichner

Let $M$ be a complete hyperbolic $n$-manifold, $n\geq 2$. Via integration over geodesic simplices, any closed bounded differential 2-form on $M$ defines a bounded cohomology class in $H^2_b(M)$. It was proved by Barge and Ghys (for $n=2$)…

Geometric Topology · Mathematics 2026-04-20 Gian Maria Dall'Ara , Roberto Frigerio , Ervin Hadziosmanovic